misuse of check-true exposed by repair to rackunit

[jbclements]

About 6 months ago, there was a repair to rackunit that exposed a number of minor bugs littered around the racket space. In the case of unlike-assets-test, it looks like there's a (check-true <expr> #t) that was supposed to just be (check-true <expr>). I'm ... not quite sure where this code lives?

Here's the change that exposed this problem:

racket/rackunit#158