sock: Introduce named constants for sk_reuse

Name them in a "backward compatible" manner, i.e. reuse or not
are still 1 and 0 respectively. The reuse value of 2 means that
the socket with it will forcibly reuse everyone else's port.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/econet/af_econet.c b/net/econet/af_econet.c
index 71b5edc..fa14ca7 100644
--- a/net/econet/af_econet.c
+++ b/net/econet/af_econet.c
@@ -617,7 +617,7 @@
 	if (sk == NULL)
 		goto out;
 
-	sk->sk_reuse = 1;
+	sk->sk_reuse = SK_CAN_REUSE;
 	sock->ops = &econet_ops;
 	sock_init_data(sock, sk);
 
@@ -1012,7 +1012,7 @@
 		return error;
 	}
 
-	udpsock->sk->sk_reuse = 1;
+	udpsock->sk->sk_reuse = SK_CAN_REUSE;
 	udpsock->sk->sk_allocation = GFP_ATOMIC; /* we're going to call it
 						    from interrupts */