[media] s2255drv: fix memory leak s2255_probe()

smatch says:
 drivers/media/usb/s2255/s2255drv.c:2246 s2255_probe() warn:
possible memory leak of 'dev'

Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>