[PATCH] Driver Core: remove driver model detach_state

The driver model has a "detach_state" mechanism that:

 - Has never been used by any in-kernel drive;
 - Is superfluous, since driver remove() methods can do the same thing;
 - Became buggy when the suspend() parameter changed semantics and type;
 - Could self-deadlock when called from certain suspend contexts;
 - Is effectively wasted documentation, object code, and headspace.

This removes that "detach_state" mechanism; net code shrink, as well
as a per-device saving in the driver model and sysfs.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/base/bus.c

@@ -390,7 +390,6 @@ void device_release_driver(struct device * dev)
 		sysfs_remove_link(&drv->kobj, kobject_name(&dev->kobj));
 		sysfs_remove_link(&dev->kobj, "driver");
 		list_del_init(&dev->driver_list);
-		device_detach_shutdown(dev);
 		if (drv->remove)
 			drv->remove(dev);
 		dev->driver = NULL;