USB: metro-usb: fix io after disconnect

Make sure no control urb is submitted during close after a disconnect by
checking the disconnected flag.

Cc: <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/serial/metro-usb.c

@@ -179,16 +179,13 @@ static void metrousb_cleanup(struct usb_serial_port *port)
 {
 	dev_dbg(&port->dev, "%s\n", __func__);
 
-	if (port->serial->dev) {
-		/* Shutdown any interrupt in urbs. */
-		if (port->interrupt_in_urb) {
 	usb_unlink_urb(port->interrupt_in_urb);
 	usb_kill_urb(port->interrupt_in_urb);
-		}
 
-		/* Send deactivate cmd to device */
+	mutex_lock(&port->serial->disc_mutex);
+	if (!port->serial->disconnected)
 		metrousb_send_unidirectional_cmd(UNI_CMD_CLOSE, port);
-	}
+	mutex_unlock(&port->serial->disc_mutex);
 }
 
 static int metrousb_open(struct tty_struct *tty, struct usb_serial_port *port)