Fixed bug with expectFailure in tasty-quickcheck

expectFailure in combination with testProperty throws the following exception:
````
FAIL
  message threw an exception: No match in record selector usedSize
````

The way I see it, there is no way to reproduce unexpected non-failure, so Tasty cannot possibly output a reproduce message. Therefore, I propose to only output the reproduce message on actual Failures, not NoExpectedFailures.