Clean up XFA code which causes warnings

xfa/fxbarcode/oned/BC_OnedUPCAReader.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 // Original code is licensed as follows:
 /*
  * Copyright 2008 ZXing authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ skipping 71 matching lines @@
                                          int32_t& e) {
   int32_t temp = m_ean13Reader->DecodeMiddle(row, startRange, resultString, e);
   BC_EXCEPTION_CHECK_ReturnValue(e, 0);
   return temp;
 }
 CFX_ByteString CBC_OnedUPCAReader::MaybeReturnResult(CFX_ByteString& result,
                                                      int32_t& e) {
   if (result[0] == '0') {
     result.Delete(0);
     return result;
-  } else {
-    e = BCExceptionFormatException;
-    return "";
   }
+  e = BCExceptionFormatException;
   return "";
 }