tty: nwpserial: Pass correct pointer to free_irq()

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>