This reverts commit 1f324e38.

It seems to cause regressions, and in particular the output path
really depends upon there being a socket attached to skb->sk for
checks such as sk_mc_loop(skb->sk) for example.  See ip6_output_finish2().
Reported-by: NStephen Warren <swarren@wwwdotorg.org>
Reported-by: NFabio Estevam <festevam@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>