don't use annoying and unneeded in C++ casts of NULL to "T *" in all other files neither

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@58227 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/scrlwing.cpp

@@ -937,7 +937,7 @@ void wxScrollHelperBase::StopAutoScrolling()
     if ( m_timerAutoScroll )
     {
         delete m_timerAutoScroll;
-        m_timerAutoScroll = (wxTimer *)NULL;
+        m_timerAutoScroll = NULL;
     }
 #endif
 }