EventCounter._validate() method is executed after being filtered by LttngEventFilter.

[atsushi421]

The following error occurs when attempting to obtain trace data for a very short duration (e.g., 1 second) by filtering.

Traceback (most recent call last):
  File "/opt/ros/galactic/bin/ros2", line 11, in <module>
    load_entry_point('ros2cli==0.13.3', 'console_scripts', 'ros2')()
  File "/opt/ros/galactic/lib/python3.8/site-packages/ros2cli/cli.py", line 67, in main
    rc = extension.main(parser=parser, args=args)
  File "/home/saitamaemb4/ros2_caret_ws/build/ros2caret/ros2caret/command/caret.py", line 32, in main
    return extension.main(args=args)
  File "/home/saitamaemb4/ros2_caret_ws/build/ros2caret/ros2caret/verb/node_summary.py", line 79, in main
    tmp_lttng = Lttng(args.trace_dir, event_filters=[
  File "/home/saitamaemb4/ros2_caret_ws/build/caret_analyze/caret_analyze/infra/lttng/lttng.py", line 187, in __init__
    self._counter = EventCounter(data, validate=validate)
  File "/home/saitamaemb4/ros2_caret_ws/build/caret_analyze/caret_analyze/infra/lttng/event_counter.py", line 34, in __init__
    self._validate()
  File "/home/saitamaemb4/ros2_caret_ws/build/caret_analyze/caret_analyze/infra/lttng/event_counter.py", line 85, in _validate
    raise InvalidTraceFormatError(
caret_analyze.exceptions.InvalidTraceFormatError: Failed to found trace point added by forked rclcpp. Measurement results will not be correct. The binary may have been compiled without using fork-rclcpp.