btrfs: remove the btrfs_delayed_ref_node container helpers

Now that we don't use these helpers anywhere, remove them.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/delayed-ref.h

@@ -399,33 +399,6 @@ void btrfs_migrate_to_delayed_refs_rsv(struct btrfs_fs_info *fs_info,
 				       u64 num_bytes);
 bool btrfs_check_space_for_delayed_refs(struct btrfs_fs_info *fs_info);
 
-/*
- * helper functions to cast a node into its container
- */
-static inline struct btrfs_delayed_tree_ref *
-btrfs_delayed_node_to_tree_ref(struct btrfs_delayed_ref_node *node)
-{
-	return &node->tree_ref;
-}
-
-static inline struct btrfs_delayed_data_ref *
-btrfs_delayed_node_to_data_ref(struct btrfs_delayed_ref_node *node)
-{
-	return &node->data_ref;
-}
-
-static inline struct btrfs_delayed_ref_node *
-btrfs_delayed_tree_ref_to_node(struct btrfs_delayed_tree_ref *ref)
-{
-	return container_of(ref, struct btrfs_delayed_ref_node, tree_ref);
-}
-
-static inline struct btrfs_delayed_ref_node *
-btrfs_delayed_data_ref_to_node(struct btrfs_delayed_data_ref *ref)
-{
-	return container_of(ref, struct btrfs_delayed_ref_node, data_ref);
-}
-
 static inline u64 btrfs_delayed_ref_owner(struct btrfs_delayed_ref_node *node)
 {
 	if (node->type == BTRFS_EXTENT_DATA_REF_KEY ||