Merge branch 'rhashtable-next'

Herbert Xu says:

====================
rhashtable: Add iterators and use them

The first patch fixes a potential crash with nft_hash destroying
the table during a shrinking process.  While the next patch adds
rhashtable iterators to replace current manual walks used by
netlink and netfilter.  The final two patches make use of these
iterators in netlink and netfilter.
====================

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