btrfs: zero out delayed node upon allocation

It's slightly cleaner to zero-out the delayed node upon allocation
than to do it by hand in btrfs_init_delayed_node() for a few members

Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/delayed-inode.c

@@ -54,16 +54,11 @@ static inline void btrfs_init_delayed_node(
 	delayed_node->root = root;
 	delayed_node->inode_id = inode_id;
 	atomic_set(&delayed_node->refs, 0);
-	delayed_node->count = 0;
-	delayed_node->flags = 0;
 	delayed_node->ins_root = RB_ROOT;
 	delayed_node->del_root = RB_ROOT;
 	mutex_init(&delayed_node->mutex);
-	delayed_node->index_cnt = 0;
 	INIT_LIST_HEAD(&delayed_node->n_list);
 	INIT_LIST_HEAD(&delayed_node->p_list);
-	delayed_node->bytes_reserved = 0;
-	memset(&delayed_node->inode_item, 0, sizeof(delayed_node->inode_item));
 }
 
 static inline int btrfs_is_continuous_delayed_item(
@@ -132,7 +127,7 @@ again:
 	if (node)
 		return node;
 
-	node = kmem_cache_alloc(delayed_node_cache, GFP_NOFS);
+	node = kmem_cache_zalloc(delayed_node_cache, GFP_NOFS);
 	if (!node)
 		return ERR_PTR(-ENOMEM);
 	btrfs_init_delayed_node(node, root, ino);