IPv6: Fix Smatch warning.

With commit d6ddef9e641d(IPv6: Fix not join all-router mcast group when forwarding set.) I check 'dev' after it's dereference that leads to a Smatch complaint:

net/ipv6/addrconf.c:438 ipv6_add_dev()
warn: variable dereferenced before check 'dev' (see line 432)

net/ipv6/addrconf.c
431 /* protected by rtnl_lock */

   432		rcu_assign_pointer(dev->ip6_ptr, ndev);
                                   ^^^^^^^^^^^^

Old dereference.

433
434 /* Join all-node multicast group */
435 ipv6_dev_mc_inc(dev, &in6addr_linklocal_allnodes);
436
437 /* Join all-router multicast group if forwarding is set
*/
438 if (ndev->cnf.forwarding && dev && (dev->flags &
IFF_MULTICAST))

                                            ^^^

Remove the check to avoid the complaint as 'dev' can't be NULL.

---
 net/ipv6/addrconf.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

index 6b8ebc5..6a3bb60 100644
@@ -435,7 +435,7 @@ static struct inet6_dev * ipv6_add_dev(struct net_device *dev)
 	ipv6_dev_mc_inc(dev, &in6addr_linklocal_allnodes);
 
 	/* Join all-router multicast group if forwarding is set */
-	if (ndev->cnf.forwarding && dev && (dev->flags & IFF_MULTICAST))
+	if (ndev->cnf.forwarding && (dev->flags & IFF_MULTICAST))
 		ipv6_dev_mc_inc(dev, &in6addr_linklocal_allrouters);
 
 	return ndev;

1.7.1

From: Li Wei <[email protected]>
Date: Thu, 08 Mar 2012 08:58:07 +0800

...

Applied.