Fix some uses of 'use-dialog-box'

Fix some uses of 'use-dialog-box'

* lisp/frame.el (display-mouse-p): Fix return value on MS-Windows
in batch invocations.
* lisp/hi-lock.el (hi-lock-unface-buffer): Don't consider
'last-nonmenu-event' being nil as a mouse event, for the purpose
of using dialog boxes.