Error messages could improved

[Chambana]

In case anyone else has this problem, make sure that your /dev/ttyUSB0 device didn't enumerate as something else (like /dev/ttyUSB1). The error message reported by this driver reported a bad baud rate, but it was actually just accessing the wrong device.

[ldlidar_stl_ros2_node-1] [INFO] [1688758790.646974464] [LD19]: <port_baudrate>: 230400
[ldlidar_stl_ros2_node-1] [INFO] [1688758790.647006204] [LD19]: <laser_scan_dir>: Counterclockwise
[ldlidar_stl_ros2_node-1] [INFO] [1688758790.647039723] [LD19]: <enable_angle_crop_func>: false
[ldlidar_stl_ros2_node-1] [INFO] [1688758790.647072149] [LD19]: <angle_crop_min>: 135.000000
[ldlidar_stl_ros2_node-1] [INFO] [1688758790.647121835] [LD19]: <angle_crop_max>: 225.000000
[ldlidar_stl_ros2_node-1] [INFO] [1688758790.654224580] [LD19]: ldlidar node start is success
[ldlidar_stl_ros2_node-1] [ERROR] [1688758793.655270233] [LD19]: ldlidar communication is abnormal.
[ldlidar_stl_ros2_node-1] [LDS][INFO][1688758790.653998746][Actual BaudRate reported:230769]
[ERROR] [ldlidar_stl_ros2_node-1]: process has died [pid 2481, exit code 1, cmd '/home/ubuntu/cart_ws/install/ldlidar_stl_ros2/lib/ldlidar_stl_ros2/ldlidar_stl_ros2_node --ros-args -r __node:=LD19 --params-file /tmp/launch_params_ap9utzk8 --params-file /tmp/launch_params_zdokq3bb --params-file /tmp/launch_params__vo80x0h --params-file /tmp/launch_params_nk_g1uu0 --params-file /tmp/launch_params_s81du90y --params-file /tmp/launch_params_t_n15d8m --params-file /tmp/launch_params_4h5nvjbn --params-file /tmp/launch_params_q7anal3e --params-file /tmp/launch_params_306abeuv'].