[PATCH] netns: fix ip_rt_frag_needed rt_is_expired

[Hugh Dickins <hugh@veritas.com>]

Running recent kernels, and using a particular vpn gateway, I've been
having to edit my mails down to get them accepted by the smtp server.

Git bisect led to commit e84f84f276473dcc673f360e8ff3203148bdf0e2 -
netns: place rt_genid into struct net.  The conversion from a != test
to rt_is_expired() put one negative too many: and now my mail works.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
---
Ingo was having strange distcc problems, might this help him too?

 net/ipv4/route.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- 2.6.26-git/net/ipv4/route.c	2008-07-26 12:31:50.000000000 +0100
+++ linux/net/ipv4/route.c	2008-07-26 13:10:04.000000000 +0100
@@ -1502,7 +1502,7 @@ unsigned short ip_rt_frag_needed(struct 
 				    rth->fl.iif != 0 ||
 				    dst_metric_locked(&rth->u.dst, RTAX_MTU) ||
 				    !net_eq(dev_net(rth->u.dst.dev), net) ||
-				    !rt_is_expired(rth))
+				    rt_is_expired(rth))
 					continue;
 
 				if (new_mtu < 68 || new_mtu >= old_mtu) {