util/syspolicy: clean up doc grammar and consistency

Updates #cleanup

Change-Id: I912574cbd5ef4d8b7417b8b2a9b9a2ccfef88840
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f