[NETNS][IPV6] fix some missing namespace

This patch adds some missing namespace

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index 5eea6fa..c11c76c 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -107,6 +107,7 @@
 		    char __user *optval, int optlen)
 {
 	struct ipv6_pinfo *np = inet6_sk(sk);
+	struct net *net = sk->sk_net;
 	int val, valbool;
 	int retv = -ENOPROTOOPT;
 
@@ -432,7 +433,7 @@
 			if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != val)
 				goto e_inval;
 
-			if (__dev_get_by_index(&init_net, val) == NULL) {
+			if (__dev_get_by_index(net, val) == NULL) {
 				retv = -ENODEV;
 				break;
 			}