fix: btrfs: move ->parent and ->ref_root into btrfs_delayed_ref_node (v6.10)

fix: btrfs: move ->parent and ->ref_root into btrfs_delayed_ref_node (v6.10)

See upstream commit:

  commit cf4f04325b2b27efa5697ba0ea4c1abdee0035b4
  Author: Josef Bacik <josef@toxicpanda.com>
  Date:   Fri Apr 12 22:57:13 2024 -0400

    btrfs: move ->parent and ->ref_root into btrfs_delayed_ref_node

    These two members are shared by both the tree refs and data refs, so
    move them into btrfs_delayed_ref_node proper.  This allows us to greatly
    simplify the comparison code, as the shared refs always only sort on
    parent, and the non shared refs always sort first on ref_root, and then
    only data refs sort on their specific fields.

Change-Id: Ib7c92cc4bb8d674ac66ccfa25c03476f7adaaf90
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>