btrfs: Replace fs_info->delayed_workers workqueue with btrfs_workqueue.

Replace the fs_info->delayed_workers with the newly created
btrfs_workqueue.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Tested-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>
diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index 451b00c..76e85d6 100644
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -1318,10 +1318,10 @@
 struct btrfs_async_delayed_work {
 	struct btrfs_delayed_root *delayed_root;
 	int nr;
-	struct btrfs_work work;
+	struct btrfs_work_struct work;
 };
 
-static void btrfs_async_run_delayed_root(struct btrfs_work *work)
+static void btrfs_async_run_delayed_root(struct btrfs_work_struct *work)
 {
 	struct btrfs_async_delayed_work *async_work;
 	struct btrfs_delayed_root *delayed_root;
@@ -1392,11 +1392,11 @@
 		return -ENOMEM;
 
 	async_work->delayed_root = delayed_root;
-	async_work->work.func = btrfs_async_run_delayed_root;
-	async_work->work.flags = 0;
+	btrfs_init_work(&async_work->work, btrfs_async_run_delayed_root,
+			NULL, NULL);
 	async_work->nr = nr;
 
-	btrfs_queue_worker(&root->fs_info->delayed_workers, &async_work->work);
+	btrfs_queue_work(root->fs_info->delayed_workers, &async_work->work);
 	return 0;
 }