hevc: add missing malloc checks and free

Conflicts:
	libavcodec/hevc.c
hevc: don't fill the SAO frame if SAO is disabled
hevc: don't overwrite top_right/bottom_left samples unnecessarily
hevc: fix wrong usages of av_dlog
cabac: add skip_bytes function used for h264/hevc PCM decoding
hevc: fix PCM support

Conflicts:
	libavcodec/hevc.c
	libavcodec/hevcdsp.h
hevc: use pixel_shift in mc functions

Conflicts:
	libavcodec/hevc.c