Compiler warning in widget.c

[Eli Zaretskii]

When compiling widget.c, GCC produces this warning:

    widget.c: In function 'update_from_various_frame_slots':
    widget.c:662: warning: assignment from incompatible pointer type

This is a real problem, IMO, because the offending line

    ew->emacs_frame.font = x->font;

assigns x->font, which is of type `struct font *' (defined on font.h) to
ew->emacs_frame.font, whose type is `XFontStruct *' (see widgetpriv.h).

Looks like another fallout of the recent font-related changes?