We have two places needing this, and a third one will come shortly.
So factor things out into a helper function to reduce code duplication.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Reviewed-by: NDaniel P. Berrange <berrange@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>