pinctrl: intel: platform: fix error path in device_for_each_child_node()

In the Linux kernel, the following vulnerability has been resolved:

pinctrl: intel: platform: fix error path in device_for_each_child_node()

The device_for_each_child_node() loop requires calls to

fwnode_handle_put() upon early returns to decrement the refcount of

the child node and avoid leaking memory if that error path is triggered.

There is one early returns within that loop in

intel_platform_pinctrl_prepare_community(), but fwnode_handle_put() is

missing.

Instead of adding the missing call, the scoped version of the loop can

be used to simplify the code and avoid mistakes in the future if new

early returns are added, as the child node is only used for parsing, and

it is never assigned.