s3:lib: avoid calling async_connect_send() again and again in open_socket_out*()

s3:lib: avoid calling async_connect_send() again and again in open_socket_out*()

There's really no need to do that!

Once connect() is called and returned EINPROGRESS, the kernel
knowns what to do and reports any state change via
TEVENT_FD_READ or TEVENT_FD_WRITE.
The actual success or failure is available via
getsockopt(.., SOL_SOCKET, SO_ERROR, ...).

Before this commit we called connect() (via async_connect_send()) again
and again until we reached the final caller provided timeout,
even if the kernel already found out that the destination is
unreachable.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>