Merge branch 'slab/for-7.2/alloc_bulk' into slab/for-next

Merge two separately sent but vaguely related patches from Christoph
Hellwig.  One changes the kmem_cache_alloc_bulk() API to return bool,
because it was already actiong as all-or-nothing, and that aspect was
not documented. Existing callers are updated.

The second patch simplifies the mempool_alloc_bulk() API to stop
skipping over non-NULL entries in the array, and removes a related
parameter that said how many are non-NULL.

A similar simplification of alloc_pages_bulk() is being discussed as
well and should follow in near future.

diff --cc mm/slub.c
Simple merge