netns: Use net_eq() to compare net-namespaces for optimization.

Without CONFIG_NET_NS, namespace is always &init_net.
Compiler will be able to omit namespace comparisons with this patch.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c
index aa33a4a..432ce9d 100644
--- a/net/ipv4/netfilter/ip_queue.c
+++ b/net/ipv4/netfilter/ip_queue.c
@@ -477,7 +477,7 @@
 {
 	struct net_device *dev = ptr;
 
-	if (dev_net(dev) != &init_net)
+	if (!net_eq(dev_net(dev), &init_net))
 		return NOTIFY_DONE;
 
 	/* Drop any packets associated with the downed device */