pps: claim parallel port exclusively

Both pps_parport and pps_gen_parport are written in a way that they
can't share a port with any other driver. This can result in locking up
the process that loads modules or even the whole kernel if the modules
are compiled in. Use PARPORT_FLAG_EXCL to indicate this.

Signed-off-by: Alexander Gordeev <[e-mail]>
Cc: Alexander Gordeev <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/pps/clients/pps_parport.c

···
 	}
 
 	device->pardev = parport_register_device(port, KBUILD_MODNAME,
-			NULL, NULL, parport_irq, 0, device);
+			NULL, NULL, parport_irq, PARPORT_FLAG_EXCL, device);
 	if (!device->pardev) {
 		pr_err("couldn't register with %s\n", port->name);
 		goto err_free;

drivers/pps/generators/pps_gen_parport.c

···
 	}
 
 	device.pardev = parport_register_device(port, KBUILD_MODNAME,
-			NULL, NULL, NULL, 0, &device);
+			NULL, NULL, NULL, PARPORT_FLAG_EXCL, &device);
 	if (!device.pardev) {
 		pr_err("couldn't register with %s\n", port->name);
 		return;