Fix bug 9900: is_printer_published GUID retrieval
Samba currently always responds to GetPrinter(level = 7) requests with
DSPRINT_UNPUBLISH, regardless of the AD publish status tracked via the
PRINTER_ATTRIBUTE_PUBLISHED flag. This is due to erroneous "objectGUID"
unmarshalling in is_printer_published().
This change splits "objectGUID" retrieval into a separate function, and
adds a pull_reg_sz() call to correctly unmarshall the GUID.
Autobuild-User(v4-0-test): Karolin Seeger <kseeger@samba.org>
Autobuild-Date(v4-0-test): Tue Jun 4 11:49:46 CEST 2013 on sn-devel-104