configure: simplify rpm build checks

Remove the --enable-rpm configuration option and define the
BUILDING_RPM build conditional directly depending on the presence of
the rpmbuild and rpm utilities.

Signed-off-by: Damien Le Moal <[email protected]>

configure.ac

@@ -38,17 +38,8 @@ CC="$PTHREAD_CC"
 # Checks for rpm package builds
 AC_PATH_PROG([RPMBUILD], [rpmbuild], [notfound])
 AC_PATH_PROG([RPM], [rpm], [notfound])
-
-AC_ARG_ENABLE([rpm],
-	[AS_HELP_STRING([--enable-rpm],
-		[Configure for building RPM package (default=no, requires rpm and rpmbuild)])],
-	[AS_IF([test "x$enable_rpm" = xyes],
-		[AS_IF([test "x$RPMBUILD" = xnotfound],
-			[AC_MSG_ERROR([rpmbuild is required for --enable-rpm])],
-		[test "x$RPM" = xnotfound],
-			[AC_MSG_ERROR([rpm is required for --enable-rpm])])])],
-	[enable_rpm=no])
-AM_CONDITIONAL(BUILDING_RPM, test "x$enable_rpm" = xyes)
+AM_CONDITIONAL([BUILDING_RPM],
+		[test "x$RPMBUILD" != xnotfound && test "x$RPM" != xnotfound])
 
 # Checks for header files
 AC_CHECK_HEADER(libgen.h, [],