Merge branch 'rhashtable-next'

Ying Xue says:

====================
remove nl_sk_hash_lock from netlink socket

After tipc socket successfully avoids the involvement of an extra lock
with rhashtable_lookup_insert(), it's possible for netlink socket to
remove its hash socket lock now. But as netlink socket needs a compare
function to look for an object, we first introduce a new function
called rhashtable_lookup_compare_insert() in commit #1 which is
implemented based on original rhashtable_lookup_insert(). We
subsequently remove nl_sk_hash_lock from netlink socket with the new
introduced function in commit #2. Lastly, as Thomas requested, we add
commit #3 to indicate the implementation of what the grow and shrink
decision function must enforce min/max shift.

v2:
 As Thomas pointed out, there was a race between checking portid and
 then setting it in commit #2. Now use socket lock to make the process
 of both checking and setting portid atomic, and then eliminate the
 race.
====================

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