/usr/share/doc/linux-image-extra-4.4.0-53-generic/changelog.Debian.gz is in linux-image-extra-4.4.0-53-generic 4.4.0-53.74.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/linux-image-extra-4.4.0-53-generic/../linux-image-4.4.0-53-generic/changelog.Debian.gz