PNP: stop using the subsystem rwsem

The rwsem is not used to protect anything, so the use of it by the PNP
subsystem isn't really useful, and it's doubtful if it really did anything or
not.  So I've removed it.

Cc: Adam Belay <ambx1@neo.rr.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/pnp/card.c

@@ -311,7 +311,6 @@ struct pnp_dev * pnp_request_card_device(struct pnp_card_link *clink, const char
 	return NULL;
 
 found:
-	down_write(&dev->dev.bus->subsys.rwsem);
 	dev->card_link = clink;
 	dev->dev.driver = &drv->link.driver;
 	if (pnp_bus_type.probe(&dev->dev))
@@ -319,14 +318,11 @@ struct pnp_dev * pnp_request_card_device(struct pnp_card_link *clink, const char
 	if (device_bind_driver(&dev->dev))
 		goto err_out;
 
-	up_write(&dev->dev.bus->subsys.rwsem);
-
 	return dev;
 
 err_out:
 	dev->dev.driver = NULL;
 	dev->card_link = NULL;
-	up_write(&dev->dev.bus->subsys.rwsem);
 	return NULL;
 }
 
@@ -340,11 +336,9 @@ void pnp_release_card_device(struct pnp_dev * dev)
 	struct pnp_card_driver * drv = dev->card_link->driver;
 	if (!drv)
 		return;
-	down_write(&dev->dev.bus->subsys.rwsem);
 	drv->link.remove = &card_remove;
 	device_release_driver(&dev->dev);
 	drv->link.remove = &card_remove_first;
-	up_write(&dev->dev.bus->subsys.rwsem);
 }
 
 /*