test/TestQuiesceAgent: free quiesce_requests Context

When sanitizer is enabled, unittest_mds_quiesce_agent fails as following

```
[==========] Running 5 tests from 1 test suite.
[----------] Global test environment set-up.
[----------] 5 tests from QuiesceAgentTest
[ RUN      ] QuiesceAgentTest.ThreadManagement
[       OK ] QuiesceAgentTest.ThreadManagement (3 ms)
[ RUN      ] QuiesceAgentTest.DbUpdates
[       OK ] QuiesceAgentTest.DbUpdates (1 ms)
[ RUN      ] QuiesceAgentTest.QuiesceProtocol
[       OK ] QuiesceAgentTest.QuiesceProtocol (3 ms)
[ RUN      ] QuiesceAgentTest.DuplicateQuiesceRequest
[       OK ] QuiesceAgentTest.DuplicateQuiesceRequest (2 ms)
[ RUN      ] QuiesceAgentTest.TimeoutBeforeComplete
[       OK ] QuiesceAgentTest.TimeoutBeforeComplete (2 ms)
[----------] 5 tests from QuiesceAgentTest (11 ms total)

[----------] Global test environment tear-down
[==========] 5 tests from 1 test suite ran. (11 ms total)
[  PASSED  ] 5 tests.

=================================================================
==3975692==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 64 byte(s) in 1 object(s) allocated from:
    #0 0xaaaadd81c7c8 in operator new(unsigned long) (/root/ceph/build/bin/unittest_mds_quiesce_agent+0x1fc7c8) (BuildId: 7d45344ba1e43661d9de484f0a5d129377c4d4ae)
    #1 0xaaaadd8878d8 in QuiesceAgent::agent_thread_main() /root/ceph/src/mds/QuiesceAgent.cc:136:68
    ceph#2 0xaaaadd86de38 in QuiesceAgent::AgentThread::entry() /root/ceph/src/mds/QuiesceAgent.h:244:24
    ceph#3 0xffff83d6b554 in Thread::entry_wrapper() /root/ceph/src/common/Thread.cc:87:10
    ceph#4 0xffff83d6b314 in Thread::_entry_func(void*) /root/ceph/src/common/Thread.cc:74:29
    ceph#5 0xffff8154d5c4 in start_thread nptl/./nptl/pthread_create.c:442:8
    ceph#6 0xffff815b5ed8  misc/../sysdeps/unix/sysv/linux/aarch64/clone.S:79

Indirect leak of 120 byte(s) in 1 object(s) allocated from:
    #0 0xaaaadd81c7c8 in operator new(unsigned long) (/root/ceph/build/bin/unittest_mds_quiesce_agent+0x1fc7c8) (BuildId: 7d45344ba1e43661d9de484f0a5d129377c4d4ae)
    #1 0xaaaadd8af4f4 in __gnu_cxx::new_allocator<std::_Sp_counted_ptr_inplace<QuiesceAgent::TrackedRoot, std::allocator<QuiesceAgent::TrackedRoot>, (__gnu_cxx::_Lock_policy)2> >::allocate(unsigned long, void const*) /usr/bin/../lib/gcc/aarch64-linux-gnu/11/../../../../include/c++/11/ext/new_allocator.h:127:27
    ceph#2 0xaaaadd8af3d8 in std::allocator<std::_Sp_counted_ptr_inplace<QuiesceAgent::TrackedRoot, std::allocator<QuiesceAgent::TrackedRoot>, (__gnu_cxx::_Lock_policy)2> >::allocate(unsigned long) /usr/bin/../lib/gcc/aarch64-linux-gnu/11/../../../../include/c++/11/bits/allocator.h:185:32
    ceph#3 0xaaaadd8af3d8 in std::allocator_traits<std::allocator<std::_Sp_counted_ptr_inplace<QuiesceAgent::TrackedRoot, std::allocator<QuiesceAgent::TrackedRoot>, (__gnu_cxx::_Lock_policy)2> > >::allocate(std::allocator<std::_Sp_counted_ptr_inplace<QuiesceAgent::TrackedRoot, std::allocator<QuiesceAgent::TrackedRoot>, (__gnu_cxx::_Lock_policy)2> >&, unsigned long) /usr/bin/../lib/gcc/aarch64-linux-gnu/11/../../../../include/c++/11/bits/alloc_traits.h:464:20
    ceph#4 0xaaaadd8aef00 in std::__allocated_ptr<std::allocator<std::_Sp_counted_ptr_inplace<QuiesceAgent::TrackedRoot, std::allocator<QuiesceAgent::TrackedRoot>, (__gnu_cxx::_Lock_policy)2> > > std::__allocate_guarded<std::allocator<std::_Sp_counted_ptr_inplace<QuiesceAgent::TrackedRoot, std::allocator<QuiesceAgent::TrackedRoot>, (__gnu_cxx::_Lock_policy)2> > >(std::allocator<std::_Sp_counted_ptr_inplace<QuiesceAgent::TrackedRoot, std::allocator<QuiesceAgent::TrackedRoot>, (__gnu_cxx::_Lock_policy)2> >&) /usr/bin/../lib/gcc/aarch64-linux-gnu/11/../../../../include/c++/11/bits/allocated_ptr.h:98:21
    ceph#5 0xaaaadd8aec14 in std::__shared_count<(__gnu_cxx::_Lock_policy)2>::__shared_count<QuiesceAgent::TrackedRoot, std::allocator<QuiesceAgent::TrackedRoot>, QuiesceState&, std::chrono::duration<unsigned long, std::ratio<1l, 1000000000l> >&>(QuiesceAgent::TrackedRoot*&, std::_Sp_alloc_shared_tag<std::allocator<QuiesceAgent::TrackedRoot> >, QuiesceState&, std::chrono::duration<unsigned long, std::ratio<1l, 1000000000l> >&) /usr/bin/../lib/gcc/aarch64-linux-gnu/11/../../../../include/c++/11/bits/shared_ptr_base.h:648:19
    ceph#6 0xaaaadd8ae988 in std::__shared_ptr<QuiesceAgent::TrackedRoot, (__gnu_cxx::_Lock_policy)2>::__shared_ptr<std::allocator<QuiesceAgent::TrackedRoot>, QuiesceState&, std::chrono::duration<unsigned long, std::ratio<1l, 1000000000l> >&>(std::_Sp_alloc_shared_tag<std::allocator<QuiesceAgent::TrackedRoot> >, QuiesceState&, std::chrono::duration<unsigned long, std::ratio<1l, 1000000000l> >&) /usr/bin/../lib/gcc/aarch64-linux-gnu/11/../../../../include/c++/11/bits/shared_ptr_base.h:1342:14
    ceph#7 0xaaaadd8ae70c in std::shared_ptr<QuiesceAgent::TrackedRoot>::shared_ptr<std::allocator<QuiesceAgent::TrackedRoot>, QuiesceState&, std::chrono::duration<unsigned long, std::ratio<1l, 1000000000l> >&>(std::_Sp_alloc_shared_tag<std::allocator<QuiesceAgent::TrackedRoot> >, QuiesceState&, std::chrono::duration<unsigned long, std::ratio<1l, 1000000000l> >&) /usr/bin/../lib/gcc/aarch64-linux-gnu/11/../../../../include/c++/11/bits/shared_ptr.h:409:4
    ceph#8 0xaaaadd8ae484 in std::shared_ptr<QuiesceAgent::TrackedRoot> std::allocate_shared<QuiesceAgent::TrackedRoot, std::allocator<QuiesceAgent::TrackedRoot>, QuiesceState&, std::chrono::duration<unsigned long, std::ratio<1l, 1000000000l> >&>(std::allocator<QuiesceAgent::TrackedRoot> const&, QuiesceState&, std::chrono::duration<unsigned long, std::ratio<1l, 1000000000l> >&) /usr/bin/../lib/gcc/aarch64-linux-gnu/11/../../../../include/c++/11/bits/shared_ptr.h:862:14
    ceph#9 0xaaaadd88ff0c in std::shared_ptr<QuiesceAgent::TrackedRoot> std::make_shared<QuiesceAgent::TrackedRoot, QuiesceState&, std::chrono::duration<unsigned long, std::ratio<1l, 1000000000l> >&>(QuiesceState&, std::chrono::duration<unsigned long, std::ratio<1l, 1000000000l> >&) /usr/bin/../lib/gcc/aarch64-linux-gnu/11/../../../../include/c++/11/bits/shared_ptr.h:878:14
    ceph#10 0xaaaadd884a6c in QuiesceAgent::db_update(QuiesceMap&) /root/ceph/src/mds/QuiesceAgent.cc:60:26
    ceph#11 0xaaaadd84a840 in QuiesceAgentTest::update(QuiesceDbVersion, std::initializer_list<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, QuiesceMap::RootInfo> >) /root/ceph/src/test/mds/TestQuiesceAgent.cc:156:18
    ceph#12 0xaaaadd84985c in QuiesceAgentTest::update(unsigned long, std::initializer_list<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, QuiesceMap::RootInfo> >) /root/ceph/src/test/mds/TestQuiesceAgent.cc:165:14
    ceph#13 0xaaaadd8288a8 in QuiesceAgentTest_DbUpdates_Test::TestBody() /root/ceph/src/test/mds/TestQuiesceAgent.cc:213:16
    ceph#14 0xaaaadd977230 in void testing::internal::HandleSehExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) /root/ceph/src/googletest/googletest/src/gtest.cc:2605:10
    ceph#15 0xaaaadd924590 in void testing::internal::HandleExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) /root/ceph/src/googletest/googletest/src/gtest.cc:2641:14
    ceph#16 0xaaaadd8d4a40 in testing::Test::Run() /root/ceph/src/googletest/googletest/src/gtest.cc:2680:5
    ceph#17 0xaaaadd8d6984 in testing::TestInfo::Run() /root/ceph/src/googletest/googletest/src/gtest.cc:2858:11
    ceph#18 0xaaaadd8d7f84 in testing::TestSuite::Run() /root/ceph/src/googletest/googletest/src/gtest.cc:3012:28
    ceph#19 0xaaaadd8f3d48 in testing::internal::UnitTestImpl::RunAllTests() /root/ceph/src/googletest/googletest/src/gtest.cc:5723:44
    ceph#20 0xaaaadd981130 in bool testing::internal::HandleSehExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) /root/ceph/src/googletest/googletest/src/gtest.cc:2605:10
    ceph#21 0xaaaadd92bb64 in bool testing::internal::HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool>(testing::internal::UnitTestImpl*, bool (testing::internal::UnitTestImpl::*)(), char const*) /root/ceph/src/googletest/googletest/src/gtest.cc:2641:14
    ceph#22 0xaaaadd8f31c0 in testing::UnitTest::Run() /root/ceph/src/googletest/googletest/src/gtest.cc:5306:10
    ceph#23 0xaaaadd820710 in RUN_ALL_TESTS() /root/ceph/src/googletest/googletest/include/gtest/gtest.h:2486:46
    ceph#24 0xaaaadd81ed3c in main /root/ceph/src/test/unit.cc:45:10
    ceph#25 0xffff814f73f8 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16
    ceph#26 0xffff814f74c8 in __libc_start_main csu/../csu/libc-start.c:392:3
    ceph#27 0xaaaadd76e6ac in _start (/root/ceph/build/bin/unittest_mds_quiesce_agent+0x14e6ac) (BuildId: 7d45344ba1e43661d9de484f0a5d129377c4d4ae)

SUMMARY: AddressSanitizer: 184 byte(s) leaked in 2 allocation(s).
```

quiesce_requests Context should be freed.

Signed-off-by: Rongqi Sun <[email protected]>

src/test/mds/TestQuiesceAgent.cc

@@ -139,13 +139,19 @@ class QuiesceAgentTest : public testing::Test {
     }
 
     void TearDown() override {
+      for (auto it = quiesce_requests.cbegin(); it != quiesce_requests.cend(); ) {
+        if (it->second.second) {
+          it->second.second->complete(-ECANCELED);
+        }
+        it = quiesce_requests.erase(it);
+      }
+
       if (agent) {
         agent->shutdown();
         agent.reset();
       }
     }
 
-
     using R = QuiesceMap::Roots::value_type;
     using RootInitList = std::initializer_list<R>;