Merge branch 'udp_tunnel_sk'

Merge branch 'udp_tunnel_sk'

Prevent UDP tunnels from operating on garbage socket

So this should do the rest of the work such that when we encapsulate
into a UDP tunnel, the output path works on the UDP tunnel's socket
rather than skb->sk.

Part of this work is based upon changes done by Jiri Pirko some time
ago.

Basically the first step is to pass the socket through the nf_hook
okfn(), and then next we do the same for the UDP tunnel xmit routines.

Signed-off-by: David S. Miller <davem@davemloft.net>