3.16.0-26.35~14.04.1) is not available, but a newer one is (3.16.0-38.52~14.04.1). We redirected you there.
/usr/lib/linux-tools/3.16.0-31-lowlatency/usbip is in linux-tools-3.16.0-31-lowlatency 3.16.0-31.43~14.04.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/linux-tools/3.16.0-31-lowlatency/../../linux-lts-utopic-tools-3.16.0-31/usbip