/usr/lib/linux-tools/4.10.0-21-generic/perf is in linux-tools-4.10.0-21-generic 4.10.0-21.23~16.04.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/linux-tools/4.10.0-21-generic/../../linux-hwe-edge-tools-4.10.0-21/perf