Make b_frame_strategy not fail on pass 2, but still print a notice.
Make b_frame_strategy not fail on pass 2, but still print a notice.

git-svn-id: a4d7c1866f8397a4106e0b57fc4fbf792bbdaaaf@5425 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

prajnashi/ffmpeg,prajnashi/ffmpeg,prajnashi/ffmpeg,prajnashi/ffmpeg