Fix devstack failure due to incorrect variable assignment
Fix devstack failure due to incorrect variable assignment

After I9c8912a8fd596535589b207d7fc553b9d951d3fe this approach leads
to a failure and breaks (at least) ironic-inspector gate.

Change-Id: I19bb8ada9a6f42d375838cc88a376715918c2a3e

noironetworks/devstack,richliu/devstack,avvocatodemarchis/devstack,dirkmueller/devstack,thomasem/devstack,Mahito/devstack,prithivm/branch01,thomasem/devstack,Mahito/devstack,group-policy/devstack,bswartz/devstack,prithivm/branch01,bigswitch/devstack,bswartz/devstack,mssumanth/devstack,pombredanne/devstack,nawawi/openstack,varunarya10/devstack,openstack-dev/devstack,pombredanne/devstack,varunarya10/devstack,bigswitch/devstack,dtroyer/devstack,samgoon/devstack,nawawi/openstack,avvocatodemarchis/devstack,group-policy/devstack,richliu/devstack,dtroyer/devstack,samgoon/devstack,dirkmueller/devstack,noironetworks/devstack,mssumanth/devstack,openstack-dev/devstack