USB: adutux: Add waiting in transfer abortion

Add waiting for an URB transmit finish that let the last URB to be sent
(to be not discarded) during 'release' procedure. W/o this waiting,the
last frame will be nearly always lost.

A test case: an attempt of sending a single frame:
echo -en "\001mk255" >/dev/adutux0
Signed-off-by: Kirill Kapranov <kirill.kirillovich.kapranov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/misc/adutux.c

@@ -132,6 +132,8 @@ static void adu_abort_transfers(struct adu_device *dev)
 	spin_lock_irqsave(&dev->buflock, flags);
 	if (!dev->out_urb_finished) {
 		spin_unlock_irqrestore(&dev->buflock, flags);
+		wait_event_timeout(dev->write_wait, dev->out_urb_finished,
+			COMMAND_TIMEOUT);
 		usb_kill_urb(dev->interrupt_out_urb);
 	} else
 		spin_unlock_irqrestore(&dev->buflock, flags);