openssl: Don't re-enter FIPS mode if we are already using it

If FIPS mode has been enabled by other means, under some environments it can't
be entered again. It fails with "FIPS mode already set". To avoid it, we first
check the mode before changing it.

src/libstrongswan/plugins/openssl/openssl_plugin.c

@@ -526,9 +526,10 @@ plugin_t *openssl_plugin_create()
 #ifdef OPENSSL_FIPS
 	if (fips_mode)
 	{
-		if (!FIPS_mode_set(fips_mode))
+		if (FIPS_mode() != fips_mode && !FIPS_mode_set(fips_mode))
 		{
-			DBG1(DBG_LIB, "unable to set openssl FIPS mode(%d)", fips_mode);
+			DBG1(DBG_LIB, "unable to set openssl FIPS mode(%d) from (%d)",
+				 fips_mode, FIPS_mode());
 			return NULL;
 		}
 	}