Function shutdown

TheForceEngine/TFE_Audio/audioSystem.cpp:140–149

	}

	void shutdown()
	{
		TFE_System::logWrite(LOG_MSG, "Audio", "Shutdown");
		if (s_nullDevice) { return; }

		stopAllSounds();

		TFE_AudioDevice::destroy();
		SDL_DestroyMutex(s_mutex);
	}

	void stopAllSounds()
	{