avcodec_align_dimensions2: Ensure cinepak has large enough buffers.

This is partly redundant with the following patches, but its safer

Found-by: u-bo1b@0w.se
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit f5c00b347dc76285c639d9878a014c40395c5228)

Conflicts:

	libavcodec/utils.c

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
cook: check js_subband_start for validity

Fixes out of array read

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit c69315a5deb0f8095e6b4746b69171d6f3059b2f)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>