build: add requirement for openssl to configure_ac

Add requirement for openssl to configure_ac so that configure will fail
when not found.

Tested: Verified OPENSSL_LIBS contained (-lssl -lcrypto).
Change-Id: I7cf3c671749801f089054be3828e9c3dea564157
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/test/Makefile.am b/test/Makefile.am
index f6d9e46..70b72c7 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -20,7 +20,7 @@
     $(SDBUSPLUS_LIBS) \
     $(PHOSPHOR_DBUS_INTERFACES_LIBS) \
     $(PHOSPHOR_LOGGING_LIBS) \
-    -lssl -lcrypto \
+    $(OPENSSL_LIBS) \
     -lgtest -lgtest_main -lgmock $(PTHREAD_CFLAGS) $(OESDK_TESTCASE_FLAGS)
 
 check_PROGRAMS =