V4L/DVB: cx25821: fix coding style issues in cx25821-video-upstream.c

This is a patch to cx25821-video-upstream.c file that fixes up warnings
and errors found by the checkpatch.pl tool

Signed-off-by: Olimpiu Pascariu <olimpiu.pascariu@gmail.com>
Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>