Get rid of NULLs in xfa/fxbarcode/

xfa/fxbarcode/qrcode/BC_QRGridSampler.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 2007 ZXing authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ skipping 110 matching lines @@
   for (int32_t y = 0; y < dimensionY; y++) {
     int32_t max = points.GetSize();
     FX_FLOAT iValue = (FX_FLOAT)(y + 0.5f);
     int32_t x;
     for (x = 0; x < max; x += 2) {
       points[x] = (FX_FLOAT)((x >> 1) + 0.5f);
       points[x + 1] = iValue;
     }
     transform->TransformPoints(&points);
     CheckAndNudgePoints(image, &points, e);
-    BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+    BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
     for (x = 0; x < max; x += 2) {
       if (image->Get((int32_t)points[x], (int32_t)points[x + 1])) {
         bits->Set(x >> 1, y);
       }
     }
   }
   return bits.release();
 }