PVS-Studio warning V503 for Asterisk

static int manager_park(....)
{
  ....
  const char *timeout = astman_get_header(m, "Timeout");
  ....
  int timeout_override = -1;
  ....
  if (sscanf(timeout, "%30d", &timeout_override) != 1 ||
    timeout < 0) {                                          //<==
      astman_send_error(s, m, "Invalid Timeout value.");
      return 0;
  }
}

This suspicious code was found in Asterisk project by PVS-Studio static code analyzer.
Warning message is:
V503 This is a nonsensical comparison: pointer < 0. parking_manager.c 520

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