change driver_lidar_bk_16z. not complete.

src/driver/driver_lidar_bk_16z/lidar_16z.cpp

@@ -123,5 +123,6 @@ void lidar_16z::ThreadDecode()
 
 int lidar_16z::GetPointCloud(pcl::PointCloud<pcl::PointXYZI>::Ptr & point_cloud)
 {
+    if(mbpcupdate == false)return 0;
     return 1;
 }