nuv: check ff_rtjpeg_decode_frame_yuv420 return value

CC: libav-stable@libav.org
(cherry picked from commit 85ac12587bfef970d0e0e4abc292df346daf8478)
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

Conflicts:
	libavcodec/nuv.c
dv: Add a guard to not overread the ppcm array

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
(cherry picked from commit 7ee191cab0dc44700f26c5784e2adeb6a779651b)
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

Conflicts:
	libavformat/dv.c
lavf: fix the comparison in an overflow check

CC: libav-stable@libav.org

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
(cherry picked from commit 26f027fba1c5ab482fa2488fbe0fa36c8bb33b69)
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>