removed a cast to WPARAM which was unnecessary and provoked a warning (part of #9803)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@54902 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/listctrl.cpp

@@ -2706,7 +2706,7 @@ static void HandleItemPaint(LPNMLVCUSTOMDRAW pLVCD, HFONT hfont)
 
     // same thing for CDIS_FOCUS (except simpler as there is only one of them)
     if ( ::GetFocus() == hwndList &&
-            ListView_GetNextItem(hwndList, (WPARAM)-1, LVNI_FOCUSED) == item )
+            ListView_GetNextItem(hwndList, -1, LVNI_FOCUSED) == item )
     {
         nmcd.uItemState |= CDIS_FOCUS;
     }