remove no more needed fields in GIFContext, patch by Daniel Verkamp, daniel at drv dot nu

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@17096 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavcodec/gif.c

@@ -139,8 +139,6 @@ static int gif_image_write_image(uint8_t **bytestream,
 }
 
 typedef struct {
-    int64_t time, file_time;
-    uint8_t buffer[100]; /* data chunks */
     AVFrame picture;
 } GIFContext;