Cleanup unused methods and return values in FWL code.

xfa/fwl/core/ifwl_datetimecalendar.cpp

Index: xfa/fwl/core/ifwl_datetimecalendar.cpp
diff --git a/xfa/fwl/core/ifwl_datetimecalendar.cpp b/xfa/fwl/core/ifwl_datetimecalendar.cpp
index 786d16860e9c7a68dda2e26df3c2e5a27ad3517e..0e095b9424264eb9618ca4345cf87df7c9feebcc 100644
--- a/xfa/fwl/core/ifwl_datetimecalendar.cpp
+++ b/xfa/fwl/core/ifwl_datetimecalendar.cpp
@@ -23,10 +23,10 @@ FWL_Error IFWL_DateTimeCalendar::Initialize() {
   return FWL_Error::Succeeded;
 }
 
-FWL_Error IFWL_DateTimeCalendar::Finalize() {
+void IFWL_DateTimeCalendar::Finalize() {
   delete m_pDelegate;
   m_pDelegate = nullptr;
-  return IFWL_MonthCalendar::Finalize();
+  IFWL_MonthCalendar::Finalize();
 }
 
 CFWL_DateTimeCalendarImpDelegate::CFWL_DateTimeCalendarImpDelegate(