Use wxDELETE() and wxDELETEA() when possible.

Use wxDELETE[A]() functions which automatically NULL out their arguments after
deleting them instead of doing it manually.

Closes #9685.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@64656 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/timer.cpp

@@ -273,7 +273,7 @@ DECLARE_DYNAMIC_CLASS(wxTimerModule)
 public:
     wxTimerModule() {}
     bool OnInit() { return true; }
-    void OnExit() { delete gs_scheduler; gs_scheduler = NULL; }
+    void OnExit() { wxDELETE(gs_scheduler); }
 };
 
 IMPLEMENT_DYNAMIC_CLASS(wxTimerModule, wxModule)