uniformize AVStream->priv_data freeing in av_close_input_stream

Originally committed as revision 13838 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/asf.c

@@ -925,7 +925,6 @@ static int asf_read_close(AVFormatContext *s)
     asf_reset_header(s);
     for(i=0;i<s->nb_streams;i++) {
         AVStream *st = s->streams[i];
-        av_free(st->priv_data);
         av_free(st->codec->palctrl);
     }
     return 0;