Clean ending of the disk in erase_node agent.
Clean ending of the disk in erase_node agent.

Change-Id: I685b587db56dbf4321b670a64ee5c01ad050f2e6
Closes-bug: #1262623

stackforge/fuel-astute,eayunstack/fuel-astute,stackforge/fuel-astute,eayunstack/fuel-astute