Return non-zero from rarch_main() on failure

All platforms that test this check for != 0

frontend/frontend.c

@@ -118,7 +118,7 @@ int rarch_main(int argc, char *argv[], void *data)
                CONTENT_MODE_LOAD_FROM_CLI,
                NULL,
                NULL))
-         return 0;
+         return 1;
    }
 
    ui_companion_driver_init_first();