build: rework gtest checks

Rework gtest checks to be modeled after openbmc/gpioplus.

Change-Id: I263bf12c0323ebee5d95b569ce28da2042bd3c1d
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/test/Makefile.am b/test/Makefile.am
index 0d36509..2144c85 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -1,11 +1,11 @@
-AM_CPPFLAGS = -I$(top_srcdir)/ \
+AM_CPPFLAGS = \
+	-I$(top_srcdir)/ \
 	$(GTEST_CFLAGS) \
 	$(GMOCK_CFLAGS)
-AM_CXXFLAGS = \
-	$(GTEST_MAIN_CFLAGS)
 AM_LDFLAGS = \
+	$(GTEST_LIBS) \
 	$(GMOCK_LIBS) \
-	$(GTEST_MAIN_LIBS) \
+	-lgmock_main \
 	$(OESDK_TESTCASE_FLAGS)
 
 # Run all 'check' test programs