\#perminv, 1 of 2: groundwork

Give the window-port side of *_update_inventory() an argument.
Calls in the core still omit that; invent.c's update_inventory()
is the only place that cares.

win/win32/winMS.h

@@ -161,7 +161,7 @@ void mswin_add_menu(winid wid, const glyph_info *glyphinfo,
                     const char *str, unsigned int itemflags);
 void mswin_end_menu(winid wid, const char *prompt);
 int mswin_select_menu(winid wid, int how, MENU_ITEM_P **selected);
-void mswin_update_inventory(void);
+void mswin_update_inventory(int);
 void mswin_mark_synch(void);
 void mswin_wait_synch(void);
 void mswin_cliparound(int x, int y);