code claims to use 32bit timestamp, lets make it also use that

Originally committed as revision 8662 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/bethsoftvid.c

@@ -40,7 +40,7 @@ typedef struct BVID_DemuxContext
 
     /** video presentation time stamp.
      * delay = 16 milliseconds * (global_delay + per_frame_delay) */
-    int64_t video_pts;
+    int video_pts;
 
     int is_finished;