[media] kinect: fix sparse warnings

drivers/media/usb/gspca/kinect.c:151:19: warning: incorrect type in assignment (different base types)
drivers/media/usb/gspca/kinect.c:152:19: warning: incorrect type in assignment (different base types)
drivers/media/usb/gspca/kinect.c:153:19: warning: incorrect type in assignment (different base types)
drivers/media/usb/gspca/kinect.c:191:13: warning: restricted __le16 degrades to integer
drivers/media/usb/gspca/kinect.c:217:16: warning: incorrect type in assignment (different base types)
drivers/media/usb/gspca/kinect.c:218:16: warning: incorrect type in assignment (different base types)

Note that this fixes a real bug where cpu_to_le16 was used instead of the correct
le16_to_cpu.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Antonio Ospite <ao2@ao2.it>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>