s4/libcli: do not use netbios name in NTLMv2 blobs w/o spnego

s4/libcli: do not use netbios name in NTLMv2 blobs w/o spnego

I have seen domain controllers rejecting NTLMv2 blobs presented to
NetrLogonSamLogonEx with LOGON_FAILURE when the MsvAvNbComputerName
was a FQDN or an IP address

I have not seen this field in NTLMv2 blobs send by Windows clients
when extended security was not available, so omitting the field
makes Samba similar to Windows.

This prevents errors with some smbtorture testcases that disable
spnego and when a target name is specified that is not a valid
netbios name.

Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Autobuild-User: Andrew Bartlett <abartlet@samba.org>
Autobuild-Date: Thu Apr 14 02:19:08 CEST 2011 on sn-devel-104