Input: parkbd - clear unused function pointers

parkbd_parport_cb is a local uninitialized structure and the member
function pointers will be pointing to arbitrary locations unless they
are cleared.

Fixes: 33ca8ab97c ("Input: parkbd - use parallel port device model")
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/serio/parkbd.c

@@ -145,6 +145,7 @@ static int parkbd_getport(struct parport *pp)
 {
 	struct pardev_cb parkbd_parport_cb;
 
+	memset(&parkbd_parport_cb, 0, sizeof(parkbd_parport_cb));
 	parkbd_parport_cb.irq_func = parkbd_interrupt;
 	parkbd_parport_cb.flags = PARPORT_FLAG_EXCL;