avcodec/utvideodec: Set pro flag based on fourcc ยท FFmpeg/FFmpeg@47b7c68

This avoids mixing 8bit variants with pro and 10bit with non pro mode. Fixes: out of array read Fixes: poc_03_30.avi Found-by: GwanYeong Kim <gy741.kim@gmail.com> Reviewed-by: Paul B Mahol &...