platform/x86: fujitsu-laptop: simplify error handling in acpi_fujitsu_laptop_add()

As LED class devices registered by fujitsu-laptop no longer depend on
the platform device, two function calls inside acpi_fujitsu_laptop_add()
can be rearranged in order to simplify error handling.

Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Jonathan Woithe <jwoithe@just42.net>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>