message: Fix Vulkan's max pooling in case of no output indices
diff: @@ -90,16 +90,10 @@ bool OpPool::forward(std::vector<Tensor>& ins,
  std::vector<Tensor>& blobs,
  std::vector<Tensor>& outs)
  {
  - for (size_t ii = 0; ii < ins.size(); ii++)
  - {
  - Tensor& inpMat = ins[ii];
  - int out_index = (pool_type_ == kPoolTypeMax) ? 2 : 1;
  - Tensor& outMat = outs[out_index * ii];
  - Tensor maskMat = (pool_type_ == kPoolTypeMax) ? outs[2 * ii + 1] : Tensor();
  - if (!forward(inpMat, outMat, maskMat))
  - return false;
  - }
  - return true;
  + Tensor& inpMat = ins[0];
  + Tensor& outMat = outs[0];
  + Tensor maskMat = outs.size() > 1 ? outs[1] : Tensor();
  + return forward(inpMat, outMat, maskMat);
  }
  bool OpPool::forward(Tensor& in, Tensor& out, Tensor& mask)
  