Fix misfit test issues
Created by: valschneider
I've been hitting some nasty issues with the misfit tests since the introduction of the rt-app buffer phase. Some (most?) of it is due to shady things I wrote in that test, so I only really have myself to blame...
I tested this by keeping tasks pinned in the last phase (IOW forcing a failure scenario), and the detected big CPU idle times were exactly what I expected, so AFAICT this works fine.