mm/sl[aou]b: Get rid of __kmem_cache_destroy

What is done there can be done in __kmem_cache_shutdown.

This affects RCU handling somewhat. On rcu free all slab allocators do
not refer to other management structures than the kmem_cache structure.
Therefore these other structures can be freed before the rcu deferred
free to the page allocator occurs.

Reviewed-by: Joonsoo Kim <[email protected]>
Signed-off-by: Christoph Lameter <[email protected]>
Signed-off-by: Pekka Enberg <[email protected]>

mm/slob.c

@@ -538,10 +538,6 @@ struct kmem_cache *__kmem_cache_create(const char *name, size_t size,
 	return c;
 }
 
-void __kmem_cache_destroy(struct kmem_cache *c)
-{
-}
-
 void *kmem_cache_alloc_node(struct kmem_cache *c, gfp_t flags, int node)
 {
 	void *b;