motion_est: more complete SAB diamond size check

This makes no difference with the current #defines.

CC: libav-stable@libav.org
Bug-Id: CID 732255
display: fix order of operands

CC: libav-stable@libav.org
Bug-Id: CID 1238828 / CID 1238832
swf: prevent theoretical double free

CC: libav-stable@libav.org
Bug-Id: CID 602000
idcin: fix return check

CC: libav-stable@libav.org
Bug-Id: CID 732198
mov: fix assigment check

CC: libav-stable@libav.org
Bug-Id: CID 1197050
dnxhdenc: check negative index

CC: libav-stable@libav.org
Bug-Id: CID 700464
png_parser: fix size of chunk_lenght

CC: libav-stable@libav.org
Bug-Id: CID 1198260
vc1dec: refactor check with missing parenthesis

Fate test updated accordingly, no visual difference.

CC: libav-stable@libav.org
Bug-Id: CID 1087087
bethsoftvid: check return value

CC: libav-stable@libav.org
Bug-Id: CID 733777
dvdsub: Do not leak on failure path

CC: libav-stable@libav.org
Bug-Id: CID 1198262
xwma: Do not leak on failure path

CC: libav-stable@libav.org
Bug-Id: CID 1087092
sol: simplify sol_codec_id

CC: libav-stable@libav.org
Bug-Id: CID 1238993
tiffenc: initialize return value
sunrastenc: mention missing break

Bug-Id: CID 732231
dpxenc: mention missing break

Bug-Id: CID 732229
flvdec: make sure to check create_stream and report the same error

CC: libav-stable@libav.org
Bug-Id: CID 732242
vp8: fix checking vp7_feature_value_size

CC: libav-stable@libav.org
Bug-Id: CID 1197061
vorbisenc: add missing parenthesis

Bug-Id: CID 1238791
ffv1enc: simplify encoder initialization

Also check return value of av_pix_fmt_desc_get.
mlpdec: check for negative index

CC: libav-stable@libav.org
Bug-Id: CID 970924