[media] cx231xx-417: Fix a gcc warning

gcc didn't like to have i++ inside a complex operation:

drivers/media/video/cx231xx/cx231xx-417.c: In function ‘cx231xx_load_firmware’:
drivers/media/video/cx231xx/cx231xx-417.c:1059: warning: operation on ‘i’ may be undefined
drivers/media/video/cx231xx/cx231xx-417.c:1061: warning: operation on ‘i’ may be undefined
drivers/media/video/cx231xx/cx231xx-417.c:1063: warning: operation on ‘i’ may be undefined

Btw, I agree with gcc, as we're using i and i++ at the same operation and,
depending on how optimization may occur, it may produce a wrong code.

While here, fix CodingStyle issues on the changed code.

Acked-by: Sri Deevi <Srinivasa.Deevi@conexant.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>