posenet_publish: use const references (#23310)

selfdrive/modeld/models/driving.cc

@@ -327,10 +327,10 @@ void model_publish(PubMaster &pm, uint32_t vipc_frame_id, uint32_t frame_id, flo
 void posenet_publish(PubMaster &pm, uint32_t vipc_frame_id, uint32_t vipc_dropped_frames,
                      const ModelOutput &net_outputs, uint64_t timestamp_eof, const bool valid) {
   MessageBuilder msg;
-  auto v_mean = net_outputs.pose.velocity_mean;
-  auto r_mean = net_outputs.pose.rotation_mean;
-  auto v_std = net_outputs.pose.velocity_std;
-  auto r_std = net_outputs.pose.rotation_std;
+  const auto &v_mean = net_outputs.pose.velocity_mean;
+  const auto &r_mean = net_outputs.pose.rotation_mean;
+  const auto &v_std = net_outputs.pose.velocity_std;
+  const auto &r_std = net_outputs.pose.rotation_std;
 
   auto posenetd = msg.initEvent(valid && (vipc_dropped_frames < 1)).initCameraOdometry();
   posenetd.setTrans({v_mean.x, v_mean.y, v_mean.z});