You’re right that there’s no option for this, as far as I can see the only way to turn off those links is to edit the plugin’s loginlock.php file and comment out (i.e. add “//” in front of) the line that says
add_action('login_form', array( &$this, 'login_lock_notice' ) );
(around line 50 of the file).
I had the same problem, and I think it’s a bug in the plugin. I was able to fix it by changing line 448 in loginlock.php, at the top of the function ll_test_new_psw from
if ( 'yes' != $this->ll_options['psw_reuse'] ) return;
to
if ( 'yes' != $this->ll_options['psw_reuse'] ) return true;
