cifs: Accept validate negotiate if server return NT_STATUS_NOT_SUPPORTED

[ Upstream commit 969ae8e8d4ee54c99134d3895f2adf96047f5bee ]

Old windows version or Netapp SMB server will return
NT_STATUS_NOT_SUPPORTED since they do not allow or implement
FSCTL_VALIDATE_NEGOTIATE_INFO. The client should accept the response
provided it's properly signed.

See
https://blogs.msdn.microsoft.com/openspecification/2012/06/28/smb3-secure-dialect-negotiation/

and

MS-SMB2 validate negotiate response processing:
https://msdn.microsoft.com/en-us/library/hh880630.aspx

Samba client had already handled it.
https://bugzilla.samba.org/attachment.cgi?id=13285&action=edit



Signed-off-by: Namjae Jeon <linkinjeon@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>