Fixup for Cinder iSCSI volumes

Cinder could only attach volumes to instances that were on the
same node. This is due to the iscsi listening address set to
0.0.0.0. Attaching the listener to a interface resolves the
problem and allows volume operations from/to any host.

Change-Id: Ia66c4f7f7278e2056d1ca3770ed2461259cca4e8