ksmbd: return unsupported error on smb1 mount

commit 39b291b8

 upstream.

ksmbd disconnect connection when mounting with vers=smb1.
ksmbd should send smb1 negotiate response to client for correct
unsupported error return. This patch add needed SMB1 macros and fill
NegProt part of the response for smb1 negotiate response.

Cc: stable@vger.kernel.org
Reported-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>