remove duplicated close code in `tcp__cleanup_async_cb`.
remove duplicated close code in `tcp__cleanup_async_cb`.

`tt->reset_fn(tt)` aka `tcp__reset` already closed the tcp handle.

NetEase/libpomelo2,NetEase/libpomelo2,NetEase/libpomelo2,NetEase/libpomelo2,NetEase/libpomelo2,NetEase/libpomelo2,NetEase/libpomelo2