/usr/share/doc/linux-tools-4.4.0-66-generic/changelog.Debian.gz is in linux-tools-4.4.0-66-generic 4.4.0-66.87~14.04.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/linux-tools-4.4.0-66-generic/../linux-lts-xenial-tools-4.4.0-66/changelog.Debian.gz