[nostalgia/player] Make error output actually check for error

src/nostalgia/player/main.cpp

@@ -36,6 +36,8 @@ int main(int argc, const char **argv) {
 	ox::Error err;
 	err = run(argc, argv);
 	oxAssert(err, "Something went wrong...");
+	if (err) {
 		oxErrf("Failure: {}\n", toStr(err));
+	}
 	return static_cast<int>(err);
 }