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

include/wx/caret.h

@@ -167,7 +167,7 @@ protected:
     // the common initialization
     void Init()
     {
-        m_window = (wxWindowBase *)NULL;
+        m_window = NULL;
         m_x = m_y = 0;
         m_width = m_height = 0;
         m_countVisible = 0;