leds: powernv: Replace of_node_put to __free

leds: powernv: Replace of_node_put to __free

Use __free for device_node values, and thus drop calls to
of_node_put.

The variable attribute __free adds a scope based cleanup to
the device node. The goal is to reduce memory management issues
in the kernel code.

The of_node_put calls were removed, and the
for_each_available_child_of_node was replaced to the equivalent
for_each_available_child_of_node_scoped which use the __free.

Suggested-by: Julia Lawall <julia.lawall@inria.fr>
Signed-off-by: MarileneGarcia <marilene.agarcia@gmail.com>
Link: https://lore.kernel.org/r/20240601031713.1307859-1-marilene.agarcia@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>