Fix some return FALSE in functions that return pointers

xfa/fxfa/parser/xfa_document_datamerger_imp.cpp

Index: xfa/fxfa/parser/xfa_document_datamerger_imp.cpp
diff --git a/xfa/fxfa/parser/xfa_document_datamerger_imp.cpp b/xfa/fxfa/parser/xfa_document_datamerger_imp.cpp
index 8d50a5a96dd0c3f2871aae630b9bf060736fbdf2..a0ff81405d224d5459393066aa499c80b74d5c18 100644
--- a/xfa/fxfa/parser/xfa_document_datamerger_imp.cpp
+++ b/xfa/fxfa/parser/xfa_document_datamerger_imp.cpp
@@ -52,7 +52,7 @@ CXFA_Node* FormValueNode_CreateChild(CXFA_Node* pValueNode, XFA_Element iType) {
   CXFA_Node* pChildNode = pValueNode->GetNodeItem(XFA_NODEITEM_FirstChild);
   if (!pChildNode) {
     if (iType == XFA_Element::Unknown)
-      return FALSE;
+      return nullptr;
     pChildNode = pValueNode->GetProperty(0, iType);
   }
   return pChildNode;