BUG/MEDIUM: tcp: Make sure we keep the polling consistent in tcp_probe_connect.

BUG/MEDIUM: tcp: Make sure we keep the polling consistent in tcp_probe_connect.

In tcp_probe_connect(), if the connection is still pending, do not disable
want_recv, we don't have any business to do so, but explicitely use
__conn_xprt_want_send(), otherwise the next time we'll reach tcp_probe_connect,
fd_send_ready() would return 0 and we would never flag the connection as
CO_FL_CONNECTED, which can lead to various problems, such as check not
completing because they consider it is not connected yet.