media: vicodec: make life easier for static analyzers

cppcheck incorrectly produces an error here:
	[drivers/media/platform/vicodec/vicodec-core.c:1677]: (error) Pointer addition with NULL pointer.

While this is actually a false positive, it doesn't hurt to
reorder the checks to make the code simpler, handling first
the error patch, where no color or alpha components are there.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>