fix a few bugs in mp3_decode and minimize alsa underruns by playing silence when switch songs

git-svn-id: https://svn.musicpd.org/mpd/trunk@1572 09075e82-0dd4-0310-85a5-a0d7c8717e4f

src/inputPlugins/ogg_plugin.c

@@ -321,9 +321,8 @@ int ogg_decode(OutputBuffer * cb, DecoderControl * dc, InputStream * inStream)
 						ov_pcm_tell(&vf)/
 						dc->audioFormat.sampleRate,
 						bitRate);
-					
-			if(dc->stop) break;
 			chunkpos = 0;
+			if(dc->stop) break;
 		}
 	}