As Rufus Swart mentioned, best way will be to use existing default report (or clone it) and use own custom Org views/Org groups where required Linux computers are added.
Cloning of default report and adding just a filter portion will doesn't work, because "sp_PMLinux_Report_ComplianceByErrata" stored procedure doesn't contain query for filter collection, therefore there will be required to create additional sp_PMLinux_Report_ComplianceByErrata2 stored procedure in database, clone existing default report, modify to use this additional stored procedure and add filter parameter and filter query in cloned report.