l2tp: make __l2tp_ip*_bind_lookup() parameters 'const'

Add const qualifier wherever possible for __l2tp_ip_bind_lookup() and
__l2tp_ip6_bind_lookup().

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/l2tp/l2tp_ip6.c b/net/l2tp/l2tp_ip6.c
index 331ccf5..2f6be6d 100644
--- a/net/l2tp/l2tp_ip6.c
+++ b/net/l2tp/l2tp_ip6.c
@@ -57,8 +57,8 @@ static inline struct l2tp_ip6_sock *l2tp_ip6_sk(const struct sock *sk)
 	return (struct l2tp_ip6_sock *)sk;
 }
 
-static struct sock *__l2tp_ip6_bind_lookup(struct net *net,
-					   struct in6_addr *laddr,
+static struct sock *__l2tp_ip6_bind_lookup(const struct net *net,
+					   const struct in6_addr *laddr,
 					   const struct in6_addr *raddr,
 					   int dif, u32 tunnel_id)
 {
@@ -67,7 +67,7 @@ static struct sock *__l2tp_ip6_bind_lookup(struct net *net,
 	sk_for_each_bound(sk, &l2tp_ip6_bind_table) {
 		const struct in6_addr *sk_laddr = inet6_rcv_saddr(sk);
 		const struct in6_addr *sk_raddr = &sk->sk_v6_daddr;
-		struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk);
+		const struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk);
 
 		if (l2tp == NULL)
 			continue;