Cleanup unused methods and return values in FWL code.

xfa/fwl/core/ifwl_datetimeedit.cpp

Index: xfa/fwl/core/ifwl_datetimeedit.cpp
diff --git a/xfa/fwl/core/ifwl_datetimeedit.cpp b/xfa/fwl/core/ifwl_datetimeedit.cpp
index a16b7294840d0474d66f9b490951defc0cb1c0d7..0097691c42552ca2c0a272825e014037ec2cfd86 100644
--- a/xfa/fwl/core/ifwl_datetimeedit.cpp
+++ b/xfa/fwl/core/ifwl_datetimeedit.cpp
@@ -20,10 +20,10 @@ FWL_Error IFWL_DateTimeEdit::Initialize() {
   return FWL_Error::Succeeded;
 }
 
-FWL_Error IFWL_DateTimeEdit::Finalize() {
+void IFWL_DateTimeEdit::Finalize() {
   delete m_pDelegate;
   m_pDelegate = nullptr;
-  return IFWL_Edit::Finalize();
+  IFWL_Edit::Finalize();
 }
 
 CFWL_DateTimeEditImpDelegate::CFWL_DateTimeEditImpDelegate(