Do not (re-)set libx264 parameter b_tff if interlaced encoding was not requested.

Reconfiguring can break x264 lossless encoding.

Fixes ticket #2165.
(cherry picked from commit 75c7e4583f4fd727d236a12763a265502fe00988)
lavc/bink: Chech for malloc failure

Based on commit 8ab2173ed141aa2c3336be7f9880340dfb8dcf5e