/usr/share/doc/liblttng-ust-dev/changelog.Debian.gz is in liblttng-ust-dev 2.0.2-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/liblttng-ust-dev/../liblttng-ust0/changelog.Debian.gz