Fixed another loopwave crash with no command line arguments

test/loopwave.c

@@ -97,7 +97,7 @@ main(int argc, char *argv[])
     }
     /* Load the wave file into memory */
     if (SDL_LoadWAV(filename, &wave.spec, &wave.sound, &wave.soundlen) == NULL) {
-        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't load %s: %s\n", argv[1], SDL_GetError());
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't load %s: %s\n", filename, SDL_GetError());
         quit(1);
     }