avcodec/bink: Fix off by 1 error in ref end

Fixes: out of array access
Fixes: 48567/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_BINK_fuzzer-6657932926517248

Alterantivly to this it is possibly to allocate a bigger array

Note: oss-fuzz assigned this issue to a unrelated theora bug so the bug number matches that

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 49487045dd)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/bink.c

@@ -870,7 +870,7 @@ static int binkb_decode_plane(BinkContext *c, AVFrame *frame, GetBitContext *gb,
 
     binkb_init_bundles(c);
     ref_start = frame->data[plane_idx];
-    ref_end   = frame->data[plane_idx] + (bh * frame->linesize[plane_idx] + bw) * 8;
+    ref_end   = frame->data[plane_idx] + (bh * frame->linesize[plane_idx] + bw - 1) * 8;
 
     for (i = 0; i < 64; i++)
         coordmap[i] = (i & 7) + (i >> 3) * stride;