[media] trivial: drivers/media/usb/gspca/gspca.c: fix the indentation of a comment

Fix indentation of a comment, put it on the same level of the code it
refers to.

Signed-off-by: Antonio Ospite <ao2@ao2.it>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>