Avoid needless construction of CFX_ByteStrings during string building

xfa/fxbarcode/pdf417/BC_PDF417DetectionResultRowIndicatorColumn.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 2013 ZXing authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ skipping 204 matching lines @@
                               barcodeRowCountUpperPart.getValue()->GetAt(0),
                               barcodeRowCountLowerPart.getValue()->GetAt(0),
                               barcodeECLevel.getValue()->GetAt(0));
   removeIncorrectCodewords(codewords, *barcodeMetadata);
   return barcodeMetadata;
 }
 FX_BOOL CBC_DetectionResultRowIndicatorColumn::isLeft() {
   return m_isLeft;
 }
 CFX_ByteString CBC_DetectionResultRowIndicatorColumn::toString() {
-  return (CFX_ByteString) "IsLeft: " + (CFX_ByteString)m_isLeft + '\n' +
+  return CFX_ByteString("IsLeft: ") + m_isLeft + '\n' +
          CBC_DetectionResultColumn::toString();
 }
 void CBC_DetectionResultRowIndicatorColumn::removeIncorrectCodewords(
     CFX_PtrArray* codewords,
     CBC_BarcodeMetadata barcodeMetadata) {
   for (int32_t codewordRow = 0; codewordRow < codewords->GetSize();
        codewordRow++) {
     CBC_Codeword* codeword = (CBC_Codeword*)codewords->GetAt(codewordRow);
     if (codeword == NULL) {
       continue;
@@ skipping 22 matching lines @@
         }
         break;
       case 2:
         if (rowIndicatorValue + 1 != barcodeMetadata.getColumnCount()) {
           codewords->SetAt(codewordRow, NULL);
         }
         break;
     }
   }
 }