[media] mceusb: plug memory leak on data transmit

Hans Petter Selasky pointed out to me that we're leaking urbs when
mce_async_out is called. Its used both for configuring the hardware and
for transmitting IR data. In the tx case, mce_request_packet actually
allocates both a urb and the transfer buffer, neither of which was being
torn down. Do that in the tx callback.

CC: Hans Petter Selasky <hselasky@c2i.net>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/rc/mceusb.c

@@ -621,6 +621,9 @@ static void mce_async_callback(struct urb *urb, struct pt_regs *regs)
 		mceusb_dev_printdata(ir, urb->transfer_buffer, 0, len, true);
 	}
 
+	/* the transfer buffer and urb were allocated in mce_request_packet */
+	kfree(urb->transfer_buffer);
+	usb_free_urb(urb);
 }
 
 /* request incoming or send outgoing usb packet - used to initialize remote */