Revert "Avoid loplugin:staticmethods in non-debug build"

This reverts commit 97df2dee, obsoleted by
cbce40e9 "Make content of OSL_ASSERT,
DBG_ASSERT, etc. visiblie in non-debug builds."

vcl/source/edit/textundo.cxx

@@ -108,7 +108,6 @@ bool TextUndoManager::Redo()
 void TextUndoManager::UndoRedoStart()
 {
     DBG_ASSERT( GetView(), "Undo/Redo: Active View?" );
-    (void) this; // avoid loplugin:staticmethods
 }
 
 void TextUndoManager::UndoRedoEnd()

vcl/source/window/event.cxx

@@ -295,7 +295,6 @@ void Window::RemoveUserEvent( ImplSVEvent * nUserEvent )
                 "Window::RemoveUserEvent(): Event doesn't send to this window or is already removed" );
     DBG_ASSERT( nUserEvent->mbCall,
                 "Window::RemoveUserEvent(): Event is already removed" );
-    (void) this; // avoid loplugin:staticmethods
 
     if ( nUserEvent->mpWindow )
     {