[NET] NETNS: Omit namespace comparision without CONFIG_NET_NS.

Introduce an inline net_eq() to compare two namespaces.
Without CONFIG_NET_NS, since no namespace other than &init_net
exists, it is always 1.

We do not need to convert 1) inline vs inline and
2) inline vs &init_net comparisons.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 4a47930..50bbf6b 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -252,7 +252,7 @@
 	sk_for_each(s, node, &unix_socket_table[hash ^ type]) {
 		struct unix_sock *u = unix_sk(s);
 
-		if (sock_net(s) != net)
+		if (!net_eq(sock_net(s), net))
 			continue;
 
 		if (u->addr->len == len &&
@@ -289,7 +289,7 @@
 		    &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
 		struct dentry *dentry = unix_sk(s)->dentry;
 
-		if (sock_net(s) != net)
+		if (!net_eq(sock_net(s), net))
 			continue;
 
 		if(dentry && dentry->d_inode == i)