[media] gspca: Use current logging styles

Add pr_fmt.
Convert usb style logging macros to pr_<level>.
Remove now unused old usb style logging macros.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>