Merge commit '5085f25ace1e74846a0de3369bedd0e22d1a1bdc'

* commit '5085f25ace1e74846a0de3369bedd0e22d1a1bdc':
  vc1: skip motion compensation when data for last picture is invalid

This commit is a noop. The crash can't be reproduced with ffmpeg.

Merged-by: James Almer <jamrial@gmail.com>