[media] mceusb: fix usbdev leak

mceusb_init_rc_dev() does usb_get_dev(), but there is no any
usb_put_dev() in the driver.

The patch tries to straighten logic. It moves usb_get_dev()
directly to mceusb_dev_probe() and adds usb_put_dev() to an error path
and to mceusb_dev_disconnect().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>