ipv6: change ipv6_stub_impl.ipv6_dst_lookup to take net argument

This patch adds net argument to ipv6_stub_impl.ipv6_dst_lookup
for use cases where sk is not available (like mpls).
sk appears to be needed to get the namespace 'net' and is optional
otherwise. This patch series changes ipv6_stub_impl.ipv6_dst_lookup
to take net argument. sk remains optional.

All callers of ipv6_stub_impl.ipv6_dst_lookup have been modified
to pass net. I have modified them to use already available
'net' in the scope of the call. I can change them to
sock_net(sk) to avoid any unintended change in behaviour if sock
namespace is different. They dont seem to be from code inspection.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/addrconf.h b/include/net/addrconf.h
index def59d3..0c3ac5a 100644
--- a/include/net/addrconf.h
+++ b/include/net/addrconf.h
@@ -158,8 +158,8 @@
 				 const struct in6_addr *addr);
 	int (*ipv6_sock_mc_drop)(struct sock *sk, int ifindex,
 				 const struct in6_addr *addr);
-	int (*ipv6_dst_lookup)(struct sock *sk, struct dst_entry **dst,
-				struct flowi6 *fl6);
+	int (*ipv6_dst_lookup)(struct net *net, struct sock *sk,
+			       struct dst_entry **dst, struct flowi6 *fl6);
 	void (*udpv6_encap_enable)(void);
 	void (*ndisc_send_na)(struct net_device *dev, struct neighbour *neigh,
 			      const struct in6_addr *daddr,