Cleanup unused methods and return values in FWL code.

xfa/fwl/core/ifwl_combolist.cpp

Index: xfa/fwl/core/ifwl_combolist.cpp
diff --git a/xfa/fwl/core/ifwl_combolist.cpp b/xfa/fwl/core/ifwl_combolist.cpp
index abe2c092d218ad9516eb5e0bc706e51bd301f303..d34a55bcc21901486d01bfde3da84ac783ffaa78 100644
--- a/xfa/fwl/core/ifwl_combolist.cpp
+++ b/xfa/fwl/core/ifwl_combolist.cpp
@@ -23,10 +23,10 @@ FWL_Error IFWL_ComboList::Initialize() {
   return FWL_Error::Succeeded;
 }
 
-FWL_Error IFWL_ComboList::Finalize() {
+void IFWL_ComboList::Finalize() {
   delete m_pDelegate;
   m_pDelegate = nullptr;
-  return IFWL_ListBox::Finalize();
+  IFWL_ListBox::Finalize();
 }
 
 int32_t IFWL_ComboList::MatchItem(const CFX_WideString& wsMatch) {