Previously, the situation was ignored, which might have had the effect that Pod
scheduling continued (?) even though the Pod+PVC weren't known to be in an
acceptable state.
When adding the ephemeral volume feature, the special case for
PersistentVolumeClaim volume sources in kubelet's host path and node
limits checks was overlooked. An ephemeral volume source is another
way of referencing a claim and has to be treated the same way.
