media: cxusb: fix several coding style issues

As this driver had a major change, let's take the opportunity
and do some coding style cleanup, in order to make it compliant
with Kernel's style.

This patch was partially done with the help of two tools:

	./scripts/checkpatch.pl --fix-inplace --strict
	astyle --indent=tab=8 --style=linux

But manually adjusted in order to fit our style.

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