3.13.0-30.55) is not available, but a newer one is (3.13.0-166.216). We redirected you there.
/usr/bin/hp-hpdio is in hplip 3.14.6-1+deb8u1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/bin/../share/hplip/hpdio.py