message: nydus-test: catch data validation failure
  Then print validating files and contents.
diff: @@ -178,6 +178,7 @@ class WorkloadGen:
  target_files.append(relpath)
  source_path = os.path.join(self.verify_dir, relpath)
  + try:
  if os.path.islink(cur_path):
  if os.readlink(cur_path) != os.readlink(source_path):
  err_cnt += 1
  @@ -191,13 +192,21 @@ class WorkloadGen:
  logging.error("Verification error. File %s", cur_path)
  assert False
  elif stat.S_ISBLK(os.stat(cur_path).st_mode):
  - assert os.stat(cur_path).st_rdev == os.stat(source_path).st_rdev
  + assert (
  + os.stat(cur_path).st_rdev == os.stat(source_path).st_rdev
  + ), f"left {os.stat(cur_path).st_rdev} while right {os.stat(source_path).st_rdev} "
  elif stat.S_ISCHR(os.stat(cur_path).st_mode):
  - assert os.stat(cur_path).st_rdev == os.stat(source_path).st_rdev
  + assert (
  + os.stat(cur_path).st_rdev == os.stat(source_path).st_rdev
  + ), f"left {os.stat(cur_path).st_rdev} while right {os.stat(source_path).st_rdev} "
  elif stat.S_ISFIFO(os.stat(cur_path).st_mode):
  pass
  elif stat.S_ISSOCK(os.stat(cur_path).st_mode):
  pass
  + except AssertionError as exp:
  + logging.warning("current %s, source %s", cur_path, source_path
  + )
  + raise exp
  cnt += 1
  @@ -341,7 +350,7 @@ class WorkloadGen:
  def read_collected_files(self, duration):
  """
  - Randomly select a file from a random direcotry which was collected
  + Randomly select a file from a random directory which was collected
  when set up this workload generator. No dir recursive read happens.
  """
  dirs_cnt = len(self._collected_dirs)
  