don't silence error unnecessary

don't silence error unnecessary

This `if` was used to separate error output from the formatting output, when they both used stdout. It was useful for integration with tools, which can submit input to stdin and read pretty printed result from stdout without worrying about errors intermingled with the actual result.

But now we write errors to `stderr`, so the problem disappears and we can safely remove this `if`.

Errors should never pass silently, unless explicitly silenced.