/usr/lib/linux-tools/4.2.0-42-generic/x86_energy_perf_policy is in linux-tools-4.2.0-42-generic 4.2.0-42.49~14.04.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/linux-tools/4.2.0-42-generic/../../linux-lts-wily-tools-4.2.0-42/x86_energy_perf_policy