Add libstdc++fs to test_ldflags Makefile var

Every testcase that uses test_ldflags also needs that library,
so just pull it in from that single place instead of in each
testcase.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I1c0ccd51ae8f79a8cf2a90ddb74316537fa957e2
diff --git a/test/Makefile.am b/test/Makefile.am
index a55e9a9..a95677d 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -24,7 +24,7 @@
 
 test_ldflags = \
 	-lgtest_main -lgtest \
-	-lgmock \
+	-lgmock -lstdc++fs \
 	$(PTHREAD_LIBS) \
 	$(OESDK_TESTCASE_FLAGS) \
 	$(PHOSPHOR_DBUS_INTERFACES_LIBS) \
@@ -51,48 +51,42 @@
 elog_errorwrap_test_SOURCES = elog_errorwrap_test.cpp
 elog_errorwrap_test_LDADD = $(test_ldadd)
 elog_errorwrap_test_LDFLAGS = \
-        $(test_ldflags) \
-        -lstdc++fs
+        $(test_ldflags)
 
 serialization_test_path_CPPFLAGS = $(test_cppflags)
 serialization_test_path_CXXFLAGS = $(test_cxxflags)
 serialization_test_path_SOURCES = serialization_test_path.cpp
 serialization_test_path_LDADD = $(test_ldadd)
 serialization_test_path_LDFLAGS = \
-	$(test_ldflags) \
-	-lstdc++fs
+	$(test_ldflags)
 
 serialization_test_properties_CPPFLAGS = $(test_cppflags)
 serialization_test_properties_CXXFLAGS = $(test_cxxflags)
 serialization_test_properties_SOURCES = serialization_test_properties.cpp
 serialization_test_properties_LDADD = $(test_ldadd)
 serialization_test_properties_LDFLAGS = \
-	$(test_ldflags) \
-	-lstdc++fs
+	$(test_ldflags)
 
 remote_logging_test_address_CPPFLAGS = $(test_cppflags)
 remote_logging_test_address_CXXFLAGS = $(test_cxxflags)
 remote_logging_test_address_SOURCES = remote_logging_test_address.cpp
 remote_logging_test_address_LDADD = $(remote_logging_test_ldadd)
 remote_logging_test_address_LDFLAGS = \
-	$(test_ldflags) \
-	-lstdc++fs
+	$(test_ldflags)
 
 remote_logging_test_port_CPPFLAGS = $(test_cppflags)
 remote_logging_test_port_CXXFLAGS = $(test_cxxflags)
 remote_logging_test_port_SOURCES = remote_logging_test_port.cpp
 remote_logging_test_port_LDADD = $(remote_logging_test_ldadd)
 remote_logging_test_port_LDFLAGS = \
-	$(test_ldflags) \
-	-lstdc++fs
+	$(test_ldflags)
 
 remote_logging_test_config_CPPFLAGS = $(test_cppflags)
 remote_logging_test_config_CXXFLAGS = $(test_cxxflags)
 remote_logging_test_config_SOURCES = remote_logging_test_config.cpp
 remote_logging_test_config_LDADD = $(remote_logging_test_ldadd)
 remote_logging_test_config_LDFLAGS = \
-	$(test_ldflags) \
-	-lstdc++fs
+	$(test_ldflags)
 
 sdjournal_mock_test_CPPFLAGS = $(test_cppflags)
 sdjournal_mock_test_CXXFLAGS = $(test_cxxflags)
@@ -112,7 +106,7 @@
 	$(top_builddir)/log_manager.o \
 	$(top_builddir)/org.openbmc.Associations.o \
 	$(top_builddir)/xyz/openbmc_project/Logging/Internal/Manager/server.o
-extensions_test_LDFLAGS = $(test_ldflags) -lstdc++fs
+extensions_test_LDFLAGS = $(test_ldflags)
 
 # TODO Remove once the test-case failure is resolved openbmc/phosphor-logging#11
 XFAIL_TESTS = elog_errorwrap_test