/usr/lib/linux-tools/4.15.0-20-lowlatency/usbipd is in linux-tools-4.15.0-20-lowlatency 4.15.0-20.21.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/linux-tools/4.15.0-20-lowlatency/../../linux-tools-4.15.0-20/usbipd