Merge branch 'rhashtable-New-features-in-walk-and-bucket'

Tom Herbert says:

====================
rhashtable: New features in walk and bucket

This patch contains some changes to related rhashtable:

- Above allow rhashtable_walk_start to return void
- Add a functon to peek at the next entry during a walk
- Abstract out function to compute a has for a table
- A library function to alloc a spinlocks bucket array
- Call the above function for rhashtable locks allocation

Tested: Exercised using various operations on an ILA xlat
table.

v2:
 - Apply feedback from Herbert. Don't change semantics of resize
   event reporting and -EAGAIN, just simplify API for callers that
   ignore those.
 - Add end_of_table in iter to reliably tell when the iterator has
   reached to the eno.
====================

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