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/os2/settings.cpp

@@ -70,8 +70,7 @@ void wxSystemSettingsModule::OnExit()
 {
     sm_optionNames.Clear();
     sm_optionValues.Clear();
-    delete gs_fontDefault;
-    gs_fontDefault = NULL;
+    wxDELETE(gs_fontDefault);
 }
 
 wxColour wxSystemSettingsNative::GetColour(