From: Pavel Emelyanov <xemul@openvz.org>
Date: Wed, 31 Oct 2007 22:23:35 +0300

> When the new pernet something (subsys, device or operations) is
> being registered, the init callback is to be called for each
> namespace, that currently exitst in the system. During the
> unregister, the same is to be done with the exit callback.
> 
> However, not every pernet something has both calls, but the
> check for the appropriate pointer to be not NULL is performed
> inside the for_each_net() loop.
> 
> This is (at least) strange, so tune this.
> 
> Signed-off-by: Pavel Emelyanov <xemul@openvz.org>

Applied.