repl: display prompt once after error callback

Do not call `.displayPrompt()` twice after the `eval` callback
resulted in an error.

(This does not affect the default eval because it doesn’t use
the callback if an error occurs.)

PR-URL: https://github.com/nodejs/node/pull/38314


Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>