mm/slab_common.c: rename cache create/destroy helpers

do_kmem_cache_create(), do_kmem_cache_shutdown(), and
do_kmem_cache_release() sound awkward for static helper functions that are
not supposed to be used outside slab_common.c.  Rename them to
create_cache(), shutdown_cache(), and release_caches(), respectively.
This patch is a pure cleanup and does not introduce any functional
changes.

Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>