Calling fake function many times resulted in StackOverflowError

Hi there,

I've noticed an issue with faked function after calling it ~10000 times.
Here code to reproduce an issue
```
(f/with-fakes
  (let [foo (f/fake [[1] 3])]
    (dotimes [_ 10000]
      (foo 1))))
```
Seems like error appeared inside `self-test-unused-fakes` function because of too many `remove` wrappers from `-mark-used`

Would you like to see an MR with fix?