FFMPEG Plugin: Code styles, typos and code deduplication.

- Kudos to stippi for taking the time pointing those out :)
  http://www.freelists.org/post/haiku-commits/haiku-hrev47576-srcaddonsmediapluginsffmpeg,1
- No functional change intended.

Signed-off-by: Colin Günther <coling@gmx.de>
HaikuPorts/x86_gcc2: Update both FFmpegs to 0.10.14-1.

Signed-off-by: Oliver Tappe <zooey@hirschkaefer.de>