slub: Add lock release annotation

The unfreeze_slab() releases page's PG_locked bit but was missing
proper annotation. The deactivate_slab() needs to be marked also
since it calls unfreeze_slab() without grabbing the lock.
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

mm/slub.c

@@ -1446,6 +1446,7 @@ static struct page *get_partial(struct kmem_cache *s, gfp_t flags, int node)
  * On exit the slab lock will have been dropped.
  */
 static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
+	__releases(bitlock)
 {
 	struct kmem_cache_node *n = get_node(s, page_to_nid(page));
 
@@ -1488,6 +1489,7 @@ static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
  * Remove the cpu slab
  */
 static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
+	__releases(bitlock)
 {
 	struct page *page = c->page;
 	int tail = 1;