dv: Replace a magic number by sizeof()
Merge commit '593d2326ef985cdffe413df629419938f7b07c4c'

* commit '593d2326ef985cdffe413df629419938f7b07c4c':
  dv: Replace a magic number by sizeof()

Conflicts:
	libavcodec/dv.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/cavs: fix B_SUB_DIRECT col-MB is Intra MB case.

in this case current MB size is forced to 16x16 (AVS standard section 9.9.1)

Signed-off-by: Yao Wang <jiayaowang@gmail.com>
Fixes Ticket 1901

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