storage: Adapt to VDO API change
storage: Adapt to VDO API change

Version 6.1.1.8 doesn't take strings anymore when sampling devices.

deryni/cockpit,moraleslazaro/cockpit,mvollmer/cockpit,cockpit-project/cockpit,SotolitoLabs/cockpit,cockpituous/cockpit,deryni/cockpit,cockpituous/cockpit,deryni/cockpit,SotolitoLabs/cockpit,cockpituous/cockpit,cockpituous/cockpit,mareklibra/cockpit,deryni/cockpit,mvollmer/cockpit,stefwalter/cockpit,moraleslazaro/cockpit,andreasn/cockpit,moraleslazaro/cockpit,SotolitoLabs/cockpit,moraleslazaro/cockpit,moraleslazaro/cockpit,martinpitt/cockpit,stefwalter/cockpit,deryni/cockpit,garrett/cockpit,cockpituous/cockpit,mareklibra/cockpit,deryni/cockpit,cockpituous/cockpit,garrett/cockpit,stefwalter/cockpit,mvollmer/cockpit,cockpit-project/cockpit,SotolitoLabs/cockpit,mvollmer/cockpit,stefwalter/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,andreasn/cockpit,andreasn/cockpit,andreasn/cockpit,martinpitt/cockpit,stefwalter/cockpit,martinpitt/cockpit,moraleslazaro/cockpit,mareklibra/cockpit,stefwalter/cockpit,garrett/cockpit,moraleslazaro/cockpit,garrett/cockpit,garrett/cockpit,martinpitt/cockpit,mvollmer/cockpit,andreasn/cockpit,deryni/cockpit,SotolitoLabs/cockpit,SotolitoLabs/cockpit,mareklibra/cockpit,andreasn/cockpit,stefwalter/cockpit,cockpit-project/cockpit,mareklibra/cockpit,mareklibra/cockpit,andreasn/cockpit,mareklibra/cockpit,martinpitt/cockpit,SotolitoLabs/cockpit