r21736: Fix the smbclient test to do something more interesting with the last

r21736: Fix the smbclient test to do something more interesting with the last
few authentication tests.  Now that the tests correctly 'fail', I was
able to fix the credentials subsystem to honour USER and PASSWD.

To get --machine-pass working, I needed ldb to always load it's static
modules, so I put this in ldb_connect().

Andrew Bartlett