message: Fix error when hunting for input parameter tensors
diff: @@ -139,7 +139,7 @@ public:
  for (int64 i=0; i<comp->num_parameters(); i++) {
  HloInstruction* param = comp->parameter_instruction(i);
  poplar::Tensor in;
  - TF_ASSIGN_OR_RETURN(in, FindInstructionOutput(tensor_map, param, o));
  + TF_ASSIGN_OR_RETURN(in, FindInstructionOutput(tensor_map, param, 0));
  if (in == out) {
  output_map[o] = i;
  