use size_t in audioOutput.c internals

src/audioOutput.c

@@ -188,7 +188,7 @@ static void convertAudioFormat(AudioOutput * audioOutput,
 					   *sizeArgPtr,
 					   &(audioOutput->outAudioFormat));
 
-	if (size > (size_t)audioOutput->convBufferLen) {
+	if (size > audioOutput->convBufferLen) {
 		audioOutput->convBuffer =
 		    xrealloc(audioOutput->convBuffer, size);
 		audioOutput->convBufferLen = size;

src/audioOutput.h

@@ -70,7 +70,7 @@ struct _AudioOutput {
 	AudioFormat reqAudioFormat;
 	ConvState convState;
 	char *convBuffer;
-	int convBufferLen;
+	size_t convBufferLen;
 	int sameInAndOutFormats;
 
 	void *data;