message: Update swoole_coroutine_util.c
diff: @@ -791,7 +791,7 @@ static PHP_METHOD(swoole_coroutine_util, fwrite)
  int fd = swoole_convert_to_fd(handle TSRMLS_CC);
  off_t _seek = lseek(fd, 0, SEEK_CUR);
  - if (length <= 0)
  + if (length <= 0 || length > l_str)
  {
  length = l_str;
  }
  