Fix test_get_device_id() failure on OSX
Fix test_get_device_id() failure on OSX

A recent change to fix a mock issue in bug 1544522 broke this test
on OSX because it's using the FQDN as cfg.HOST.host.

Change-Id: Ib6098abb16511c91865382834e25d2b96d3eab94
Closes-bug: #1549364

mahak/neutron,openstack/neutron,MaximNevrov/neutron,cloudbase/neutron,MaximNevrov/neutron,cloudbase/neutron,eayunstack/neutron,openstack/neutron,wolverineav/neutron,wolverineav/neutron,noironetworks/neutron,klmitch/neutron,bigswitch/neutron,eayunstack/neutron,sebrandon1/neutron,igor-toga/local-snat,bigswitch/neutron,noironetworks/neutron,mahak/neutron,openstack/neutron,mahak/neutron,klmitch/neutron,huntxu/neutron,huntxu/neutron,igor-toga/local-snat,sebrandon1/neutron