smb3: do not set NTLMSSP_VERSION flag for negotiate not auth request

The NTLMSSP_NEGOTIATE_VERSION flag only needs to be sent during
the NTLMSSP NEGOTIATE (not the AUTH) request, so filter it out for
NTLMSSP AUTH requests. See MS-NLMP 2.2.1.3

This fixes a problem found by the gssntlmssp server.

Link: https://github.com/gssapi/gss-ntlmssp/issues/95


Fixes: 52d00533 ("smb3: send NTLMSSP version information")
Acked-by: Roy Shterman <roy.shterman@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>