make IPv6 unit test work on systems with eth0
make IPv6 unit test work on systems with eth0

fixes bug 1103074

The link local unit test was failing because it depended on eth0 to
exists.  This mocks getaddrinfo() to ensure a consistent return value
across testing environments.

Change-Id: Ie1a4d837efcacac8c8d2217c164ad751922e1a5f

silenci/neutron,leeseuljeong/leeseulstack_neutron,projectcalico/calico-neutron,barnsnake351/neutron,NeCTAR-RC/neutron,vveerava/Openstack,glove747/liberty-neutron,CiscoSystems/vespa,jacknjzhou/neutron,cisco-openstack/neutron,rossella/neutron,citrix-openstack-build/neutron,vbannai/neutron,yamt/neutron,sasukeh/neutron,wenhuizhang/neutron,bigswitch/neutron,wenhuizhang/neutron,citrix-openstack-build/neutron,vivekanand1101/neutron,cloudbase/neutron-virtualbox,eayunstack/neutron,waltBB/neutron_read,watonyweng/neutron,kaiweifan/vse-lbaas-plugin-poc,SmartInfrastructures/neutron,mandeepdhami/neutron,yamahata/neutron,rickerc/neutron_audit,rossella/neutron,Comcast/neutron,cloudbase/neutron,pnavarro/neutron,Juniper/contrail-dev-neutron,glove747/liberty-neutron,Brocade-OpenSource/OpenStack-DNRM-Neutron,tpaszkowski/quantum,tpaszkowski/quantum,kaiweifan/neutron,mandeepdhami/neutron,SmartInfrastructures/neutron,gkotton/neutron,huntxu/neutron,magic0704/neutron,takeshineshiro/neutron,kaiweifan/vse-lbaas-plugin-poc,liqin75/vse-vpnaas-plugin,mahak/neutron,dims/neutron,leeseulstack/openstack,eayunstack/neutron,antonioUnina/neutron,ykaneko/quantum,netscaler/neutron,igor-toga/local-snat,apporc/neutron,ntt-sic/neutron,armando-migliaccio/neutron,blueboxgroup/neutron,Juniper/neutron,vbannai/neutron,eonpatapon/neutron,yamt/neutron,jerryz1982/neutron,blueboxgroup/neutron,waltBB/neutron_read,aristanetworks/neutron,ykaneko/quantum,yamt/neutron,vijayendrabvs/hap,beagles/neutron_hacking,mmnelemane/neutron,jumpojoy/neutron,leeseuljeong/leeseulstack_neutron,miyakz1192/neutron,yanheven/neutron,kaiweifan/vse-lbaas-plugin-poc,wolverineav/neutron,vivekanand1101/neutron,vveerava/Openstack,SamYaple/neutron,Juniper/neutron,gkotton/neutron,NeCTAR-RC/neutron,huntxu/neutron,oeeagle/quantum,ntt-sic/neutron,shahbazn/neutron,cisco-openstack/neutron,tpaszkowski/quantum,zhhf/charging,vbannai/neutron,beagles/neutron_hacking,dhanunjaya/neutron,ntt-sic/neutron,vijayendrabvs/ssl-neutron,kaiweifan/neutron,gopal1cloud/neutron,CiscoSystems/neutron,apporc/neutron,ykaneko/neutron,watonyweng/neutron,bigswitch/neutron,pnavarro/neutron,klmitch/neutron,virtualopensystems/neutron,vijayendrabvs/hap,CiscoSystems/neutron,gkotton/neutron,jacknjzhou/neutron,blueboxgroup/neutron,yamahata/tacker,javaos74/neutron,vijayendrabvs/hap,jerryz1982/neutron,sebrandon1/neutron,CiscoSystems/vespa,igor-toga/local-snat,armando-migliaccio/neutron,asgard-lab/neutron,dims/neutron,JioCloud/neutron,yuewko/neutron,armando-migliaccio/neutron,sebrandon1/neutron,redhat-openstack/neutron,Metaswitch/calico-neutron,vveerava/Openstack,javaos74/neutron,cernops/neutron,shahbazn/neutron,ykaneko/quantum,rossella/neutron,suneeth51/neutron,mattt416/neutron,kaiweifan/neutron,antonioUnina/neutron,takeshineshiro/neutron,yamahata/tacker,wolverineav/neutron,bgxavier/neutron,eonpatapon/neutron,JioCloud/neutron,noironetworks/neutron,barnsnake351/neutron,noironetworks/neutron,redhat-openstack/neutron,asgard-lab/neutron,vijayendrabvs/ssl-neutron,virtualopensystems/neutron,neoareslinux/neutron,beagles/neutron_hacking,armando-migliaccio/neutron,Juniper/contrail-dev-neutron,Comcast/neutron,miyakz1192/neutron,CiscoSystems/vespa,yuewko/neutron,yamahata/tacker,sajuptpm/neutron-ipam,projectcalico/calico-neutron,suneeth51/neutron,ykaneko/quantum,yamahata/neutron,ykaneko/neutron,MaximNevrov/neutron,Metaswitch/calico-neutron,bgxavier/neutron,klmitch/neutron,aristanetworks/neutron,silenci/neutron,neoareslinux/neutron,alexandrucoman/vbox-neutron-agent,CiscoSystems/neutron,netscaler/neutron,yamahata/neutron,netscaler/neutron,mmnelemane/neutron,mattt416/neutron,yanheven/neutron,SamYaple/neutron,dhanunjaya/neutron,sasukeh/neutron,leeseulstack/openstack,rdo-management/neutron,mahak/neutron,infobloxopen/neutron,openstack/neutron,openstack/neutron,magic0704/neutron,chitr/neutron,cernops/neutron,CiscoSystems/quantum,CiscoSystems/quantum,openstack/neutron,JianyuWang/neutron,ykaneko/neutron,Juniper/contrail-dev-neutron,vijayendrabvs/ssl-neutron,Stavitsky/neutron,yamt/neutron,infobloxopen/neutron,liqin75/vse-vpnaas-plugin,kaiweifan/vse-lbaas-plugin-poc,skyddv/neutron,Brocade-OpenSource/OpenStack-DNRM-Neutron,cloudbase/neutron,rossella/neutron,swdream/neutron,Juniper/neutron,swdream/neutron,tpaszkowski/quantum,gopal1cloud/neutron,liqin75/vse-vpnaas-plugin,Brocade-OpenSource/OpenStack-DNRM-Neutron,citrix-openstack-build/neutron,virtualopensystems/neutron,JianyuWang/neutron,MaximNevrov/neutron,Comcast/neutron,rickerc/neutron_audit,skyddv/neutron,rdo-management/neutron,liqin75/vse-vpnaas-plugin,paninetworks/neutron,adelina-t/neutron,leeseulstack/openstack,zhhf/charging,zhhf/charging,sajuptpm/neutron-ipam,jumpojoy/neutron,rickerc/neutron_audit,sajuptpm/neutron-ipam,adelina-t/neutron,cloudbase/neutron-virtualbox,CiscoSystems/quantum,leeseuljeong/leeseulstack_neutron,mahak/neutron,chitr/neutron,paninetworks/neutron,Stavitsky/neutron,oeeagle/quantum,alexandrucoman/vbox-neutron-agent