[media] drivers/media/video/stk-webcam.c: coding style issue

checkpatch.pl gave some coding style errors, so on the way to the first
patch I added the fix to them.

Signed-off-by: Arvydas Sidorenko <asido4@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>