Input: sun4i-lradc-keys - switch to for_each_child_of_node_scoped

Input: sun4i-lradc-keys - switch to for_each_child_of_node_scoped

Use the scoped variant of the macro to simplify the code and error
handling. This makes the error handling more robust by ensuring that
the child node is always freed.

Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Link: https://lore.kernel.org/r/20241010-input_automate_of_node_put-v1-3-ebc62138fbf8@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>