Corrected Show Hint Widget Position

The removed code is buggy because the 'curTop' variable is absolute with respect to the window currently visible to the user, where 'hints.style.top' is absolute with respect to the entire page.
Therefore, directly assigning 'hints.style.top' to 'curTop - height), would result in random positioning of the show-hint widget.

Refer to issue :- https://github.com/marijnh/CodeMirror/issues/2662