ensure tty_curs() behaves the same whether DEBUG defined or not
when it comes to positioning the cursor.
The return statement, in the debug case only, was preventing
the cursor from being moved following a range check, so the
next output was written whereever the cursor happened to be
previously.
The messaging that detects the failed range check will get
written in the DEBUG defined case hopefully allowing resolution
to the range check failure, but now the cmov will still
be attempted just as it is in the case where DEBUG is not
defined.
4e086caceb