mm: simplify list initialization in barn_shrink()

In barn_shrink(), use LIST_HEAD() to declare and initialize the
list_head in one step instead of using INIT_LIST_HEAD() separately.

No functional change.

Signed-off-by: Baolin Liu <liubaolin@kylinos.cn>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

Author: murphy12138

mm/slub.c

@@ -3032,14 +3032,11 @@ static void barn_init(struct node_barn *barn)
 
 static void barn_shrink(struct kmem_cache *s, struct node_barn *barn)
 {
-	struct list_head empty_list;
-	struct list_head full_list;
+	LIST_HEAD(empty_list);
+	LIST_HEAD(full_list);
 	struct slab_sheaf *sheaf, *sheaf2;
 	unsigned long flags;
 
-	INIT_LIST_HEAD(&empty_list);
-	INIT_LIST_HEAD(&full_list);
-
 	spin_lock_irqsave(&barn->lock, flags);
 
 	list_splice_init(&barn->sheaves_full, &full_list);