of: overlay: Fix missing of_node_put() in error case of init_overlay_changeset()

In init_overlay_changeset(), the variable "node" is from
of_get_child_by_name(), and the "node" should be discarded in error case.

Fixes: d1651b03 ("of: overlay: add overlay symbols to live device tree")
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Link: https://lore.kernel.org/r/20230602020502.11693-1-hayashi.kunihiko@socionext.com


Signed-off-by: Rob Herring <robh@kernel.org>