[media] mceusb: fix memory leaks in error path

Fix urb and transfer-buffer leaks in an urb-submission error path which
may be hit when a device is disconnected.

Fixes: 66e89522 ("V4L/DVB: IR: add mceusb IR receiver driver")

Cc: stable <stable@vger.kernel.org>     # 2.6.36
Cc: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>