net: some optimizations in af_inet

1) Use eq_net() in inet_netns_ok() to speedup socket creation if
   !CONFIG_NET_NS

2) Reorder the tests about inet_ehash_secret generation (once only)
   Use the unlikely() macro when testing if inet_ehash_secret already
   generated.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/af_inet.c

@@ -245,7 +245,7 @@ static inline int inet_netns_ok(struct net *net, int protocol)
 	int hash;
 	struct net_protocol *ipprot;
 
-	if (net == &init_net)
+	if (net_eq(net, &init_net))
 		return 1;
 
 	hash = protocol & (MAX_INET_PROTOS - 1);
@@ -272,10 +272,9 @@ static int inet_create(struct net *net, struct socket *sock, int protocol)
 	int try_loading_module = 0;
 	int err;
 
-	if (sock->type != SOCK_RAW &&
-	    sock->type != SOCK_DGRAM &&
-	    !inet_ehash_secret)
-		build_ehash_secret();
+	if (unlikely(!inet_ehash_secret))
+		if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
+			build_ehash_secret();
 
 	sock->state = SS_UNCONNECTED;