Revert "Relocate volume to compliant datastore"

Commit 4be8913520f5e9fe4109ade101da9509e4a83360 introduced a regression
which causes failures during cinder volume re-attach. This patch reverts
commit 4be8913520f5e9fe4109ade101da9509e4a83360 as an immediate fix.

Closes-Bug: #1379830
Change-Id: I5dfbd45533489c3c81db8d256bbfd2f85614a357