libvirt: stub out VIR_SECRET_USAGE_TYPE_ISCSI for older libvirt
libvirt: stub out VIR_SECRET_USAGE_TYPE_ISCSI for older libvirt

The LibvirtDistroSupportMatrix says we support at least 0.9.8 on Ubuntu
Precise 12.04 LTS and on that version the VIR_SECRET_USAGE_TYPE_ISCSI
constant is not defined in libvirt.h.in so we need to mock it out in the
tests that are using it until we've completely removed any chance of
using a native libvirt and rely solely on fakelibvirt for stubbing out
these values in unit tests.

Closes-Bug: #1422385

Change-Id: Ifb519caf7456cfc8beabdd48df8a86c78150b3db

gooddata/openstack-nova,Tehsmash/nova,sebrandon1/nova,blueboxgroup/nova,JioCloud/nova_test_latest,akash1808/nova_test_latest,devendermishrajio/nova,klmitch/nova,petrutlucian94/nova,takeshineshiro/nova,alexandrucoman/vbox-nova-driver,edulramirez/nova,cernops/nova,eonpatapon/nova,takeshineshiro/nova,BeyondTheClouds/nova,Francis-Liu/animated-broccoli,vmturbo/nova,rahulunair/nova,tudorvio/nova,jianghuaw/nova,gooddata/openstack-nova,cloudbase/nova,cyx1231st/nova,adelina-t/nova,mahak/nova,alaski/nova,fnordahl/nova,iuliat/nova,thomasem/nova,vmturbo/nova,joker946/nova,ted-gould/nova,rahulunair/nova,scripnichenko/nova,kimjaejoong/nova,dims/nova,CEG-FYP-OpenStack/scheduler,rajalokan/nova,raildo/nova,raildo/nova,bgxavier/nova,jeffrey4l/nova,bigswitch/nova,edulramirez/nova,cyx1231st/nova,yatinkumbhare/openstack-nova,TwinkleChawla/nova,klmitch/nova,LoHChina/nova,BeyondTheClouds/nova,jeffrey4l/nova,NeCTAR-RC/nova,scripnichenko/nova,openstack/nova,petrutlucian94/nova,LoHChina/nova,JianyuWang/nova,Juniper/nova,NeCTAR-RC/nova,nikesh-mahalka/nova,affo/nova,mikalstill/nova,mahak/nova,JianyuWang/nova,iuliat/nova,akash1808/nova,CloudServer/nova,zaina/nova,cernops/nova,bgxavier/nova,zhimin711/nova,jianghuaw/nova,double12gzh/nova,devendermishrajio/nova_test_latest,yatinkumbhare/openstack-nova,varunarya10/nova_test_latest,phenoxim/nova,cloudbase/nova,orbitfp7/nova,ruslanloman/nova,openstack/nova,j-carpentier/nova,mikalstill/nova,Yusuke1987/openstack_template,joker946/nova,whitepages/nova,phenoxim/nova,barnsnake351/nova,jianghuaw/nova,fnordahl/nova,tudorvio/nova,dawnpower/nova,zaina/nova,noironetworks/nova,openstack/nova,JioCloud/nova_test_latest,yosshy/nova,zzicewind/nova,akash1808/nova_test_latest,shail2810/nova,shail2810/nova,CCI-MOC/nova,JioCloud/nova,isyippee/nova,orbitfp7/nova,mikalstill/nova,mandeepdhami/nova,hanlind/nova,dawnpower/nova,belmiromoreira/nova,ted-gould/nova,kimjaejoong/nova,Stavitsky/nova,klmitch/nova,alexandrucoman/vbox-nova-driver,alaski/nova,CCI-MOC/nova,tealover/nova,double12gzh/nova,zzicewind/nova,devendermishrajio/nova,JioCloud/nova,felixma/nova,Juniper/nova,alvarolopez/nova,felixma/nova,zhimin711/nova,Yusuke1987/openstack_template,cloudbase/nova,devendermishrajio/nova_test_latest,dims/nova,apporc/nova,jianghuaw/nova,watonyweng/nova,belmiromoreira/nova,affo/nova,cernops/nova,isyippee/nova,akash1808/nova,mahak/nova,yosshy/nova,adelina-t/nova,vmturbo/nova,tangfeixiong/nova,j-carpentier/nova,tealover/nova,vmturbo/nova,BeyondTheClouds/nova,bigswitch/nova,MountainWei/nova,Juniper/nova,blueboxgroup/nova,ruslanloman/nova,Tehsmash/nova,sebrandon1/nova,mandeepdhami/nova,watonyweng/nova,rajalokan/nova,apporc/nova,barnsnake351/nova,rajalokan/nova,alvarolopez/nova,Francis-Liu/animated-broccoli,MountainWei/nova,rahulunair/nova,CloudServer/nova,CEG-FYP-OpenStack/scheduler,mmnelemane/nova,klmitch/nova,whitepages/nova,nikesh-mahalka/nova,mmnelemane/nova,hanlind/nova,TwinkleChawla/nova,tangfeixiong/nova,cloudbase/nova-virtualbox,gooddata/openstack-nova,Stavitsky/nova,hanlind/nova,varunarya10/nova_test_latest,cloudbase/nova-virtualbox,eonpatapon/nova,Juniper/nova,rajalokan/nova,noironetworks/nova,gooddata/openstack-nova,thomasem/nova,sebrandon1/nova