Fixed a problem in iSCSI multipath

Multipathing during copy image to volume and copy volume to image
operations doesn't work properly if there are different targets
associated with different portals for a mulitpath device.

Change-Id: I65c93f3788020c944db0d3a55063a6415554ff11
Closes-Bug: #1266048
Remove unused message from iogrp_data setup

The iogrp_data is initialized during do_setup loaded.
The vdisk_count is originally used but later removed.
In ValueException raised, the variable is no longer required.
Remove this will give a clearer message when 
ValueException raised.

Change-Id: Ib7b6c6a870ddd7932e8da1436d615f9ee458bd93
Closes-Bug: #1266321
Merge "Fixed a problem in iSCSI multipath"
Merge "Remove unused message from iogrp_data setup"
(Test commit) Change README to reflect Jio's fork of Cinder

Change-Id: I3f26c0a736e63725aec24ca2fa12c707b8e6460f