[media] go7007: fix sparse warnings

drivers/media/usb/go7007/go7007-usb.c:699:30: warning: cast to restricted __le16
drivers/media/usb/go7007/go7007-usb.c:769:38: warning: cast to restricted __le16
drivers/media/usb/go7007/go7007-usb.c:770:39: warning: cast to restricted __le16

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>