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 <lasaine@lvk.cs.msu.su>
Cc: Alexander Gordeev <lasaine@lvk.cs.msu.su>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/pps/clients/pps_parport.c

@@ -163,7 +163,7 @@ static void parport_attach(struct parport *port)
 	}
 
 	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;