tty: nwpserial: Pass correct pointer to free_irq()

free_irq() expects the same pointer that was passed to request_irq(), otherwise
the IRQ is not freed.

The issue was found using the following coccinelle script:

<smpl>
@r1@
type T;
T devid;
@@
request_irq(..., devid)

@r2@
type r1.T;
T devid;
position p;
@@
free_irq@p(..., devid)

@@
position p != r2.p;
@@
*free_irq@p(...)
</smpl>

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/nwpserial.c

@@ -199,7 +199,7 @@ static void nwpserial_shutdown(struct uart_port *port)
 	dcr_write(up->dcr_host, UART_IER, up->ier);
 
 	/* free irq */
-	free_irq(up->port.irq, port);
+	free_irq(up->port.irq, up);
 }
 
 static int nwpserial_verify_port(struct uart_port *port,