flv: K&R formatting cosmetics
aac: K&R formatting cosmetics
vp9: Read the frame size as unsigned

Sample-Id: 00001723-google
Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
swscale: Fix an undefined behaviour

Prevent a division by zero down the codepath.

Sample-Id: 00001721-google
Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
mathematics: K&R formatting cosmetics