update to libnut API, don't free the streams

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@7087 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavformat/libnut.c

@@ -291,7 +291,6 @@ static int nut_read_close(AVFormatContext *s) {
     NUTContext * priv = s->priv_data;
 
     nut_demuxer_uninit(priv->nut);
-    av_free(priv->s);
 
     return 0;
 }