Updates the documentation for CSI snapshot data movement for OpenShift
on IBM Cloud.
The default hostpath /var/lib/kubelet/pods cannot find
PersistentVolumeClaims with volumeMode: Block on host.
The correct hostpath for OpenShift on IBM Cloud is
/var/data/kubelet/pods.
Signed-off-by: Michael Fruchtman <msfrucht@us.ibm.com>