Pure Storage - Fix disconnect error in clustered environments
Pure Storage - Fix disconnect error in clustered environments

When arrays are configured into a synchrous cluster relationship
a disconnect of a volume that is of a non-replicated type will
cause a failure. This will also happen when attempting a volume
retype over multiple backends.

Change-Id: I2a3fa8909a9104c464fd0bbc83c61ded94f81765
Closes-Bug: #1850697

openstack/cinder,mahak/cinder,mahak/cinder,openstack/cinder