Remove useless and confusing (since they are also used in gxfenc.c) /* gxf.c */ comment.

Originally committed as revision 16053 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/gxf.h

@@ -22,7 +22,6 @@
 #ifndef AVFORMAT_GXF_H
 #define AVFORMAT_GXF_H
 
-/* gxf.c */
 typedef enum {
     PKT_MAP         = 0xbc,
     PKT_MEDIA       = 0xbf,