hwmon: (ltc2991) use device_for_each_child_node_scoped()

hwmon: (ltc2991) use device_for_each_child_node_scoped()

Switch to the _scoped() version introduced in commit 365130fd47af
("device property: Introduce device_for_each_child_node_scoped()")
to remove the need for manual calling of fwnode_handle_put() in the
paths where the code exits the loop early.

Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://lore.kernel.org/r/20240404-hwmon_device_for_each_child_node_scoped-v1-1-53997abde43c@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>