avformat/matroskaenc: remove bogus prores tag

Fixes: ffmpeg -i input -c:v prores output.mkv

Signed-off-by: Paul B Mahol <onemda@gmail.com>
swscale/utils: use memcpy instead of loop in sws_cloneVec()

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>