smb3: send CAP_DFS capability during session setup

commit 8d33096a460d5b9bd13300f01615df5bb454db10 upstream.

We had a report of a server which did not do a DFS referral
because the session setup Capabilities field was set to 0
(unlike negotiate protocol where we set CAP_DFS).  Better to
send it session setup in the capabilities as well (this also
more closely matches Windows client behavior).

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>