/usr/share/doc/linux-tools-3.13.0-55-generic/changelog.Debian.gz is in linux-tools-3.13.0-55-generic 3.13.0-55.94.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/linux-tools-3.13.0-55-generic/../linux-tools-3.13.0-55/changelog.Debian.gz