Merge commit '92888e9ed4ea4e761ae953bbe28c85cc658abc8f' into release/2.2

* commit '92888e9ed4ea4e761ae953bbe28c85cc658abc8f':
  gifdec: refactor interleave end handling

Conflicts:
	libavcodec/gifdec.c

See: 8f1457864b
Merged-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/gifdec.c

@@ -269,7 +269,7 @@ static int gif_read_image(GifState *s, AVFrame *frame)
                 break;
             }
             while (y1 >= height) {
-                y1 = 4 >> pass;
+                y1  = 4 >> pass;
                 ptr = ptr1 + linesize * y1;
                 pass++;
             }