[PATCH] kobject: add add_hotplug_env_var()

[PATCH] kobject: add add_hotplug_env_var()

Add a (non-inlined) add_hotplug_env_var() function to <linux/kobject.h>
and lib/kobject.c.  There's a lot of boilerplate code involved in
setting environment variables in a hotplug method, so we should have a
convenience function to consolidate it (and avoid subtle bugs).

Signed-off-by: Roland Dreier <roland@topspin.com>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>