software/kvm: fix aio and cache parameter for direct disk access

This fixes 157dd7ab.
3 jobs for 1.0
Status Job ID Name Coverage
  External
passed SlapOS.SlapRunner.ResilienceTest-Master

failed SlapOS.SlapRunner.ResilienceTest-Master.ERP5

00:31:21

passed SlapOS.SoftwareReleases.IntegrationTest-Master.Python3

06:58:13