ksmbd: disable SMB2_GLOBAL_CAP_ENCRYPTION for SMB 3.1.1

ksmbd: disable SMB2_GLOBAL_CAP_ENCRYPTION for SMB 3.1.1

commit 83912d6d55be10d65b5268d1871168b9ebe1ec4b upstream.

According to the official Microsoft MS-SMB2 document section 3.3.5.4, this
flag should be used only for 3.0 and 3.0.2 dialects. Setting it for 3.1.1
is a violation of the specification.

This causes my Windows 10 client to detect an anomaly in the negotiation,
and disable encryption entirely despite being explicitly enabled in ksmbd,
causing all data transfers to go in plain text.

Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3")
Cc: stable@vger.kernel.org # v5.15
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Marcos Del Sol Vives <marcos@orca.pet>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>