type check error for arguments mistakenly passed as `tune()`

[simonpcouch]

On R-release:

  Condition
-   Error:
+   Error in `feature_fraction_bynode < 1`:
-   ! The supplied `mtry` parameter is a call to `tune`. Did you forget to optimize hyperparameters with a tuning function like `tune::tune_grid`?
+   ! comparison (<) is not possible for language types