USB: fix usb_unlink_urb() usage in mct_u232 driver

Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/usb/serial/mct_u232.c

@@ -480,9 +480,9 @@ static void mct_u232_close (struct usb_serial_port *port, struct file *filp)
 
 	if (port->serial->dev) {
 		/* shutdown our urbs */
-		usb_unlink_urb (port->write_urb);
-		usb_unlink_urb (port->read_urb);
-		usb_unlink_urb (port->interrupt_in_urb);
+		usb_kill_urb(port->write_urb);
+		usb_kill_urb(port->read_urb);
+		usb_kill_urb(port->interrupt_in_urb);
 	}
 } /* mct_u232_close */