audit-util: check correct errno

(cherry picked from commit 190a0953808608b099f9465f9e786e4efe276c26)
(cherry picked from commit c90ae08b0a5f2844504a109f71dcd773c16d8260)
(cherry picked from commit a3872e6)

src/basic/audit-util.c

@@ -99,7 +99,7 @@ static int try_audit_request(int fd) {
 
         n = recvmsg_safe(fd, &mh, 0);
         if (n < 0)
-                return -errno;
+                return n;
         if (n != NLMSG_LENGTH(sizeof(struct nlmsgerr)))
                 return -EIO;