message: Add quotes around the type
  Summary: Put quotes around the element type, and change the tag to match
  Test Plan: None
  Reviewers: markp
diff: @@ -248,7 +248,7 @@ void PrintTensorMapping(const poplar::Graph& graph,
  ss << "{\"tile_id\": " << tileIdx << ", "
  << "\"num_intervals\": " << tile.size() << ", "
  << "\"num_elements\": " << tileElementCount << ", "
  - << "\"element_size\": " << elementType << "}";
  + << "\"element_type\": \"" << elementType << "\"}";
  first_tile = false;
  totalElements += tileElementCount;
  }
  