Minor cleanup and warning removal

git-svn-id: svn://svn.code.sf.net/p/sc2/code/trunk@699 8092fc87-c524-0410-9efc-e669fe64eaf9

sc2/src/sc2code/libs/sound/mixsdl/sound_mixsdl.c

@@ -288,6 +288,7 @@ NoSound_PlaybackTaskFunc (void *data)
 			SDL_Delay (delay);
 	}
 
+	HFree (stream);
 	FinishTask (task);
 	return 0;
 }

sc2/src/sc2code/libs/sound/openal/sound_openal.c

@@ -105,6 +105,8 @@ TFB_alInitSound (int driver, int flags)
 	StreamDecoderTask = AssignTask (StreamDecoderTaskFunc, 1024, 
 		"audio stream decoder");
 
+	(void) driver; // eat compiler warning
+
 	return 0;
 }
 
@@ -113,7 +115,11 @@ TFB_alUninitSound (void)
 {
 	int i;
 
-	ConcludeTask (StreamDecoderTask);
+	if (StreamDecoderTask)
+	{
+		ConcludeTask (StreamDecoderTask);
+		StreamDecoderTask = NULL;
+	}
 
 	for (i = 0; i < NUM_SOUNDSOURCES; ++i)
 	{