winbind: Use domain name from lsa query for sid_to_name cache entry

winbind: Use domain name from lsa query for sid_to_name cache entry

When winbindd is asked to map a name like realm.com\name to a SID ,that
is sucessfully resolved through the lsa lookup name call. The same call
also returns the short domain name (netbios name of the domain). Use
that short domain name for the sid_to_name cache entry, so that
subsequent sid_to_name queries return the expected netbiosname\name
result and not realm.com\name.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13831

Signed-off-by: Christof Schmitt <cs@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>