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/decnet/af_decnet.c b/net/decnet/af_decnet.c
index 61b7df5..3c23ab3 100644
--- a/net/decnet/af_decnet.c
+++ b/net/decnet/af_decnet.c
@@ -2089,7 +2089,7 @@
 {
 	struct net_device *dev = (struct net_device *)ptr;
 
-	if (dev_net(dev) != &init_net)
+	if (!net_eq(dev_net(dev), &init_net))
 		return NOTIFY_DONE;
 
 	switch(event) {