Merge branch 'tcp-2nd-listener-hash'

Martin KaFai Lau says:

====================
tcp: Add a 2nd listener hashtable (port+addr)

This patch set adds a 2nd listener hashtable.  It is to resolve
the performance issue when a process is listening at many IP
addresses with the same port (e.g. [IP1]:443, [IP2]:443... [IPN]:443)

v2:
- Move the new lhash2 and lhash2_mask before the existing
  listening_hash to avoid adding another cacheline
  to inet_hashinfo (Suggested by Eric Dumazet, Thanks!)
- I take this chance to plug an existing 4 bytes hole while
  adding 'unsigned int lhash2_mask'.
- Add some comments about lhash2 in inet_hashtables.h
====================

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