use free()/malloc() instead of realloc()

When growing the audioOutput->convBuffer, we can use free()+malloc()
instead of realloc(), which saves a memcpy().

git-svn-id: https://svn.musicpd.org/mpd/trunk@7295 09075e82-0dd4-0310-85a5-a0d7c8717e4f

src/audioOutput.c

@@ -189,8 +189,9 @@ static void convertAudioFormat(AudioOutput * audioOutput,
 					   &(audioOutput->outAudioFormat));
 
 	if (size > audioOutput->convBufferLen) {
-		audioOutput->convBuffer =
-		    xrealloc(audioOutput->convBuffer, size);
+		if (audioOutput->convBuffer != NULL)
+			free(audioOutput->convBuffer);
+		audioOutput->convBuffer = xmalloc(size);
 		audioOutput->convBufferLen = size;
 	}