Fixed attach volume for EMC SMI-S iSCSI driver

This problem was encountered during Grizzly RC1 testing.  The driver
didn't find the correct target IQN.  As a result, Nova couldn't find
the matching path in /dev/disk/by-path and therefore detached the volume.

Change-Id: I8bcf6d9896b9d445f6376ecc3a5695be46507663
Fixes: bug #1157912
(cherry picked from commit 18bf0b386b2f26f524ebb6ab540941f64cad4642)
Merge "Fixed attach volume for EMC SMI-S iSCSI driver" into milestone-proposed