Merge branch 'ipv6-mc_forwarding-changes'

Eric Dumazet says:

====================
ipv6: mc_forwarding changes

First patch removes minor data-races, as mc_forwarding can
be locklessly read in fast path.

Second patch adds a short cut in ip6mr_sk_done()
====================

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