message: changed CHECK_NOTNULL to DCHECK
diff: @@ -410,7 +410,8 @@ class MklConcatOp : public OpKernel {
  }
  AllocateOutputSetMklShape(context, 0, &dst_tensor, tf_shape_dst,
  dnn_shape_dst);
  - CHECK_NOTNULL(dst_tensor);
  + DCHECK(dst_tensor == nullptr)
  + << "Output tensor pointer is NULL";
  dst_md =
  dnn_shape_dst.IsMklTensor() ? dnn_shape_dst.GetMklLayout() : dst_md;
  @@ -446,7 +447,8 @@ class MklConcatOp : public OpKernel {
  AllocateOutputSetMklShape(context, 0, &dst_tensor, tf_shape_dst,
  dnn_shape_dst);
  - CHECK_NOTNULL(dst_tensor);
  + DCHECK(dst_tensor == nullptr)
  + << "Output tensor pointer is NULL";
  }
  } catch (mkldnn::error& e) {
  