message: Tests: add usage note to check-rpc-mappings.py
diff: @@ -90,6 +90,10 @@ def process_mapping(fname):
  return cmds
  def main():
  + if len(sys.argv) != 2:
  + print('Usage: {} ROOT-DIR'.format(sys.argv[0]), file=sys.stderr)
  + sys.exit(1)
  +
  root = sys.argv[1]
  # Get all commands from dispatch tables
  