Fix memleak

Closes issue 102

Originally committed as revision 10719 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/asf.c

@@ -878,10 +878,13 @@ static int asf_read_packet(AVFormatContext *s, AVPacket *pkt)
     return 0;
 }
 
+static void asf_reset_header(AVFormatContext *s);
+
 static int asf_read_close(AVFormatContext *s)
 {
     int i;
 
+    asf_reset_header(s);
     for(i=0;i<s->nb_streams;i++) {
         AVStream *st = s->streams[i];
         av_free(st->priv_data);