Btrfs: pass delayed_refs directly to btrfs_find_delayed_ref_head

All we need is @delayed_refs, all callers have get it ahead of calling
btrfs_find_delayed_ref_head since lock needs to be acquired firstly,
there is no reason to deference it again inside the function.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index c66f487..a1b9ef2 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -909,11 +909,8 @@ int btrfs_add_delayed_extent_op(struct btrfs_fs_info *fs_info,
  * the head node if any where found, or NULL if not.
  */
 struct btrfs_delayed_ref_head *
-btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr)
+btrfs_find_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs, u64 bytenr)
 {
-	struct btrfs_delayed_ref_root *delayed_refs;
-
-	delayed_refs = &trans->transaction->delayed_refs;
 	return find_ref_head(&delayed_refs->href_root, bytenr, 0);
 }