loplugin:vclwidgets workaround

workaround "OutputDevice subclass should have nothing in it's destructor
but a call to disposeOnce()."

Change-Id: Icc7e09ea4dec3292b62d1aba4dc881220c115414

include/vcl/button.hxx

@@ -37,7 +37,7 @@ class ImplCommonButtonData;
 class VCL_DLLPUBLIC Button : public Control
 {
 private:
-    ImplCommonButtonData *mpButtonData;
+    std::unique_ptr<ImplCommonButtonData> mpButtonData;
     Link maClickHdl;
 
     /// Command URL (like .uno:Save) in case the button should handle it.

vcl/source/control/button.cxx

@@ -88,15 +88,14 @@ ImplCommonButtonData::~ImplCommonButtonData()
 }
 
 Button::Button( WindowType nType ) :
-    Control( nType )
+    Control( nType ),
+    mpButtonData( new ImplCommonButtonData )
 {
-    mpButtonData = new ImplCommonButtonData;
 }
 
 Button::~Button()
 {
     disposeOnce();
-    delete mpButtonData;
 }
 
 void Button::dispose()