Plug memory leak in NUT muxer and demuxer

Originally committed as revision 22174 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/nutdec.c

@@ -901,6 +901,7 @@ static int nut_read_close(AVFormatContext *s)
 
     av_freep(&nut->time_base);
     av_freep(&nut->stream);
+    ff_nut_free_sp(nut);
     for(i = 1; i < nut->header_count; i++)
         av_freep(&nut->header[i]);