acpi-build: fix array leak

The free_ranges array is used as a temporary pointer array, the segment
should still be freed, however, it shouldn't free the elements themself.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Marcel Apfelbaum <marcel@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
