fortuna.c: Fix braino of mine where the reseeds would happen far
too often, making the kernel process way too busy.
random_harvestq.c: Limit the amount of "fast" entropy. We don't
need nearly as much for security, and the excess just slows things
down badly.
PR: 230808
Submitted by: Conrad Meyer <cem@FreeBSD.org> (fortuna.c) rwmaillists@googlemail.com (random_harvestq.c, but tweeked by me)
Reported by: Danilo Egea Gondolfo <danilo@FreeBSD.org>