message: reset log_fd when failed to open log_file
diff: @@ -25,6 +25,7 @@ int swLog_init(char *logfile)
  if (SwooleG.log_fd < 0)
  {
  printf("open(%s) failed. Error: %s[%d]\n", logfile, strerror(errno), errno);
  + SwooleG.log_fd = 0;
  return SW_ERR;
  }
  return SW_OK;
  