fix potential memory leak of AudioStreamPlaybackBusDetails in AudioServer::start_playback_stream()

servers/audio_server.cpp

@@ -1131,8 +1131,10 @@ void AudioServer::start_playback_stream(Ref<AudioStreamPlayback> p_playback, Map
 	AudioStreamPlaybackBusDetails *new_bus_details = new AudioStreamPlaybackBusDetails();
 	int idx = 0;
 	for (KeyValue<StringName, Vector<AudioFrame>> pair : p_bus_volumes) {
-		ERR_FAIL_COND(pair.value.size() < channel_count);
-		ERR_FAIL_COND(pair.value.size() != MAX_CHANNELS_PER_BUS);
+		if (pair.value.size() < channel_count || pair.value.size() != MAX_CHANNELS_PER_BUS) {
+			delete new_bus_details;
+			ERR_FAIL();
+		}
 
 		new_bus_details->bus_active[idx] = true;
 		new_bus_details->bus[idx] = pair.key;