From: Daniel Lezcano <redacted>
Date: Tue, 30 Oct 2007 17:21:40 +0100

When a network namespace reference is held by a network subsystem,
and when this reference is decremented in a rcu update callback, we
must ensure that there is no more outstanding rcu update before 
trying to free the network namespace.

In the normal case, the rcu_barrier is called when the network namespace
is exiting in the cleanup_net function.

But when a network namespace creation fails, and the subsystems are
undone (like the cleanup), the rcu_barrier is missing.

This patch adds the missing rcu_barrier.

Signed-off-by: Daniel Lezcano <redacted>

Applied, thanks Daniel.