Remove lio_initiator_iqns

This is a holdover from the initial LIO implementation
which did not manage ACLs sufficiently.  This is
unneeded now and handled by:
67dd248 LIO iSCSI initiator ACL auto-config

DocImpact: remove lio_initiator_iqns cfg opt

Closes-Bug: #1390383

Change-Id: I3b7fe4765c1c568a6a7713f86cadece52b130911
Merge "Remove lio_initiator_iqns"