Fix libvirt test on systems with real iSCSI devices
Fix libvirt test on systems with real iSCSI devices

The test_libvirt_kvm_iser_volume_with_multipath_getmpdev() test
expects a system with no real iSCSI devices. It actually triggers
an os.walk() of /dev/disk/by-path/ip-*, which will return any
iSCSI devices on the system. Since the test expects none, this
will cause the test to fail.

This patch just stubs that out to return an empty list always.

Change-Id: Ibb3fd18207d013c35487a3eebb336b5f288b703a
Closes-bug: #1234834

petrutlucian94/nova,phenoxim/nova,isyippee/nova,vladikr/nova_drafts,silenceli/nova,berrange/nova,whitepages/nova,cloudbase/nova-virtualbox,scripnichenko/nova,angdraug/nova,Juniper/nova,fnordahl/nova,klmitch/nova,mmnelemane/nova,Stavitsky/nova,blueboxgroup/nova,badock/nova,mikalstill/nova,jeffrey4l/nova,bgxavier/nova,vmturbo/nova,JianyuWang/nova,jianghuaw/nova,sebrandon1/nova,CEG-FYP-OpenStack/scheduler,petrutlucian94/nova_dev,akash1808/nova,felixma/nova,JioCloud/nova_test_latest,eharney/nova,rajalokan/nova,redhat-openstack/nova,berrange/nova,mgagne/nova,nikesh-mahalka/nova,JianyuWang/nova,JioCloud/nova,alaski/nova,Juniper/nova,belmiromoreira/nova,joker946/nova,eharney/nova,j-carpentier/nova,alexandrucoman/vbox-nova-driver,maelnor/nova,takeshineshiro/nova,affo/nova,iuliat/nova,eayunstack/nova,redhat-openstack/nova,tealover/nova,ruslanloman/nova,TwinkleChawla/nova,akash1808/nova,varunarya10/nova_test_latest,sebrandon1/nova,CCI-MOC/nova,cernops/nova,vmturbo/nova,dims/nova,Yuriy-Leonov/nova,Metaswitch/calico-nova,tangfeixiong/nova,iuliat/nova,whitepages/nova,virtualopensystems/nova,jianghuaw/nova,leilihh/novaha,tanglei528/nova,nikesh-mahalka/nova,rahulunair/nova,Yusuke1987/openstack_template,cloudbau/nova,openstack/nova,cloudbau/nova,saleemjaveds/https-github.com-openstack-nova,tanglei528/nova,adelina-t/nova,raildo/nova,jianghuaw/nova,ntt-sic/nova,yosshy/nova,CiscoSystems/nova,kimjaejoong/nova,viggates/nova,ted-gould/nova,Juniper/nova,mgagne/nova,petrutlucian94/nova_dev,mahak/nova,rajalokan/nova,OpenAcademy-OpenStack/nova-scheduler,LoHChina/nova,BeyondTheClouds/nova,Tehsmash/nova,takeshineshiro/nova,tealover/nova,OpenAcademy-OpenStack/nova-scheduler,cloudbase/nova-virtualbox,bigswitch/nova,akash1808/nova_test_latest,viggates/nova,edulramirez/nova,hanlind/nova,CCI-MOC/nova,zhimin711/nova,citrix-openstack-build/nova,rrader/nova-docker-plugin,JioCloud/nova_test_latest,rajalokan/nova,zhimin711/nova,openstack/nova,ruslanloman/nova,LoHChina/nova,vladikr/nova_drafts,cernops/nova,JioCloud/nova,tudorvio/nova,mikalstill/nova,akash1808/nova_test_latest,MountainWei/nova,belmiromoreira/nova,spring-week-topos/nova-week,leilihh/nova,petrutlucian94/nova,gooddata/openstack-nova,Yusuke1987/openstack_template,shail2810/nova,isyippee/nova,phenoxim/nova,klmitch/nova,spring-week-topos/nova-week,joker946/nova,sebrandon1/nova,zaina/nova,hanlind/nova,kimjaejoong/nova,zzicewind/nova,thomasem/nova,shail2810/nova,adelina-t/nova,imsplitbit/nova,Tehsmash/nova,mahak/nova,cyx1231st/nova,maelnor/nova,thomasem/nova,projectcalico/calico-nova,mahak/nova,luogangyi/bcec-nova,cloudbase/nova,projectcalico/calico-nova,barnsnake351/nova,CiscoSystems/nova,ewindisch/nova,silenceli/nova,Metaswitch/calico-nova,vmturbo/nova,gooddata/openstack-nova,bigswitch/nova,mikalstill/nova,mandeepdhami/nova,cloudbase/nova,sacharya/nova,cyx1231st/nova,Francis-Liu/animated-broccoli,Juniper/nova,dawnpower/nova,watonyweng/nova,blueboxgroup/nova,devoid/nova,dims/nova,saleemjaveds/https-github.com-openstack-nova,sacharya/nova,NeCTAR-RC/nova,rrader/nova-docker-plugin,mandeepdhami/nova,shahar-stratoscale/nova,openstack/nova,cloudbase/nova,BeyondTheClouds/nova,devendermishrajio/nova_test_latest,gooddata/openstack-nova,apporc/nova,Stavitsky/nova,badock/nova,tianweizhang/nova,klmitch/nova,zzicewind/nova,rahulunair/nova,ntt-sic/nova,vmturbo/nova,felixma/nova,MountainWei/nova,yatinkumbhare/openstack-nova,leilihh/novaha,orbitfp7/nova,apporc/nova,leilihh/nova,Yuriy-Leonov/nova,yosshy/nova,devendermishrajio/nova,tudorvio/nova,alvarolopez/nova,bgxavier/nova,mmnelemane/nova,devoid/nova,zaina/nova,noironetworks/nova,noironetworks/nova,affo/nova,NeCTAR-RC/nova,raildo/nova,j-carpentier/nova,eonpatapon/nova,eayunstack/nova,CloudServer/nova,TwinkleChawla/nova,eonpatapon/nova,dawnpower/nova,gooddata/openstack-nova,imsplitbit/nova,shahar-stratoscale/nova,edulramirez/nova,CEG-FYP-OpenStack/scheduler,double12gzh/nova,alaski/nova,ewindisch/nova,rahulunair/nova,devendermishrajio/nova_test_latest,devendermishrajio/nova,luogangyi/bcec-nova,BeyondTheClouds/nova,rajalokan/nova,cernops/nova,citrix-openstack-build/nova,jianghuaw/nova,virtualopensystems/nova,CloudServer/nova,yatinkumbhare/openstack-nova,scripnichenko/nova,tangfeixiong/nova,barnsnake351/nova,hanlind/nova,varunarya10/nova_test_latest,alvarolopez/nova,watonyweng/nova,orbitfp7/nova,fnordahl/nova,double12gzh/nova,tianweizhang/nova,Francis-Liu/animated-broccoli,angdraug/nova,jeffrey4l/nova,alexandrucoman/vbox-nova-driver,klmitch/nova,ted-gould/nova