Remove unused function require_instance_exists
Remove unused function require_instance_exists

Change-Id: I9862daebaadca4af0c1ec47ddb66e329cdce98a7

bgxavier/nova,JioCloud/nova,redhat-openstack/nova,saleemjaveds/https-github.com-openstack-nova,blueboxgroup/nova,rajalokan/nova,Yuriy-Leonov/nova,mikalstill/nova,fnordahl/nova,rahulunair/nova,bigswitch/nova,Stavitsky/nova,DirectXMan12/nova-hacking,ewindisch/nova,maoy/zknova,cloudbase/nova-virtualbox,yatinkumbhare/openstack-nova,angdraug/nova,houshengbo/nova_vmware_compute_driver,cloudbase/nova-virtualbox,rickerc/nova_audit,eayunstack/nova,zzicewind/nova,maoy/zknova,aristanetworks/arista-ovs-nova,shail2810/nova,aristanetworks/arista-ovs-nova,yatinkumbhare/openstack-nova,Stavitsky/nova,yosshy/nova,aristanetworks/arista-ovs-nova,MountainWei/nova,Tehsmash/nova,devendermishrajio/nova_test_latest,cyx1231st/nova,sebrandon1/nova,rahulunair/nova,shahar-stratoscale/nova,plumgrid/plumgrid-nova,CEG-FYP-OpenStack/scheduler,maoy/zknova,vmturbo/nova,TwinkleChawla/nova,sridevikoushik31/nova,scripnichenko/nova,projectcalico/calico-nova,LoHChina/nova,tangfeixiong/nova,rajalokan/nova,rajalokan/nova,cloudbase/nova,bigswitch/nova,sridevikoushik31/nova,luogangyi/bcec-nova,rahulunair/nova,ewindisch/nova,BeyondTheClouds/nova,felixma/nova,klmitch/nova,tudorvio/nova,MountainWei/nova,sebrandon1/nova,Juniper/nova,berrange/nova,Tehsmash/nova,Yusuke1987/openstack_template,felixma/nova,jianghuaw/nova,zhimin711/nova,apporc/nova,Juniper/nova,belmiromoreira/nova,CCI-MOC/nova,mahak/nova,jianghuaw/nova,alvarolopez/nova,openstack/nova,fajoy/nova,mgagne/nova,spring-week-topos/nova-week,silenceli/nova,dstroppa/openstack-smartos-nova-grizzly,Brocade-OpenSource/OpenStack-DNRM-Nova,citrix-openstack-build/nova,hanlind/nova,bclau/nova,openstack/nova,projectcalico/calico-nova,devendermishrajio/nova_test_latest,tangfeixiong/nova,yrobla/nova,cloudbau/nova,Yusuke1987/openstack_template,apporc/nova,Metaswitch/calico-nova,zaina/nova,Metaswitch/calico-nova,eayunstack/nova,devoid/nova,eonpatapon/nova,vmturbo/nova,eonpatapon/nova,luogangyi/bcec-nova,takeshineshiro/nova,imsplitbit/nova,gspilio/nova,watonyweng/nova,badock/nova,orbitfp7/nova,ted-gould/nova,yrobla/nova,BeyondTheClouds/nova,devendermishrajio/nova,DirectXMan12/nova-hacking,mandeepdhami/nova,watonyweng/nova,hanlind/nova,BeyondTheClouds/nova,klmitch/nova,leilihh/nova,cernops/nova,angdraug/nova,mahak/nova,ted-gould/nova,DirectXMan12/nova-hacking,vladikr/nova_drafts,mikalstill/nova,citrix-openstack-build/nova,Francis-Liu/animated-broccoli,tanglei528/nova,eharney/nova,barnsnake351/nova,tianweizhang/nova,Juniper/nova,cyx1231st/nova,ntt-sic/nova,TieWei/nova,qwefi/nova,raildo/nova,akash1808/nova,isyippee/nova,berrange/nova,dstroppa/openstack-smartos-nova-grizzly,alaski/nova,JianyuWang/nova,OpenAcademy-OpenStack/nova-scheduler,TwinkleChawla/nova,varunarya10/nova_test_latest,klmitch/nova,Francis-Liu/animated-broccoli,Juniper/nova,varunarya10/nova_test_latest,phenoxim/nova,jeffrey4l/nova,NeCTAR-RC/nova,tealover/nova,dims/nova,Triv90/Nova,Triv90/Nova,Brocade-OpenSource/OpenStack-DNRM-Nova,zzicewind/nova,jeffrey4l/nova,thomasem/nova,CiscoSystems/nova,cloudbau/nova,maheshp/novatest,mandeepdhami/nova,shootstar/novatest,sridevikoushik31/openstack,plumgrid/plumgrid-nova,maelnor/nova,joker946/nova,TieWei/nova,devoid/nova,gooddata/openstack-nova,yrobla/nova,belmiromoreira/nova,double12gzh/nova,tanglei528/nova,affo/nova,fajoy/nova,rickerc/nova_audit,virtualopensystems/nova,nikesh-mahalka/nova,petrutlucian94/nova_dev,ruslanloman/nova,SUSE-Cloud/nova,shahar-stratoscale/nova,dawnpower/nova,alexandrucoman/vbox-nova-driver,virtualopensystems/nova,klmitch/nova,mahak/nova,mmnelemane/nova,tudorvio/nova,cloudbase/nova,zaina/nova,dstroppa/openstack-smartos-nova-grizzly,imsplitbit/nova,gooddata/openstack-nova,adelina-t/nova,bclau/nova,iuliat/nova,iuliat/nova,maelnor/nova,raildo/nova,viggates/nova,JianyuWang/nova,sridevikoushik31/openstack,vmturbo/nova,eharney/nova,CloudServer/nova,NeCTAR-RC/nova,whitepages/nova,nikesh-mahalka/nova,rrader/nova-docker-plugin,alaski/nova,edulramirez/nova,mmnelemane/nova,SUSE-Cloud/nova,noironetworks/nova,mikalstill/nova,bgxavier/nova,sacharya/nova,redhat-openstack/nova,jianghuaw/nova,spring-week-topos/nova-week,gooddata/openstack-nova,akash1808/nova_test_latest,barnsnake351/nova,petrutlucian94/nova,sridevikoushik31/nova,vladikr/nova_drafts,saleemjaveds/https-github.com-openstack-nova,maheshp/novatest,dawnpower/nova,double12gzh/nova,blueboxgroup/nova,CiscoSystems/nova,rrader/nova-docker-plugin,cloudbase/nova,thomasem/nova,alexandrucoman/vbox-nova-driver,leilihh/novaha,CCI-MOC/nova,zhimin711/nova,leilihh/novaha,kimjaejoong/nova,joker946/nova,j-carpentier/nova,viggates/nova,maheshp/novatest,badock/nova,alvarolopez/nova,hanlind/nova,yosshy/nova,JioCloud/nova_test_latest,silenceli/nova,akash1808/nova_test_latest,qwefi/nova,CEG-FYP-OpenStack/scheduler,noironetworks/nova,JioCloud/nova_test_latest,adelina-t/nova,edulramirez/nova,gspilio/nova,leilihh/nova,sacharya/nova,fajoy/nova,phenoxim/nova,tianweizhang/nova,houshengbo/nova_vmware_compute_driver,gooddata/openstack-nova,Yuriy-Leonov/nova,affo/nova,JioCloud/nova,petrutlucian94/nova_dev,jianghuaw/nova,dims/nova,petrutlucian94/nova,fnordahl/nova,shootstar/novatest,sridevikoushik31/openstack,LoHChina/nova,tealover/nova,cernops/nova,shail2810/nova,ruslanloman/nova,CloudServer/nova,orbitfp7/nova,rajalokan/nova,OpenAcademy-OpenStack/nova-scheduler,cernops/nova,vmturbo/nova,gspilio/nova,akash1808/nova,scripnichenko/nova,ntt-sic/nova,isyippee/nova,devendermishrajio/nova,sridevikoushik31/nova,kimjaejoong/nova,houshengbo/nova_vmware_compute_driver,whitepages/nova,Triv90/Nova,sebrandon1/nova,j-carpentier/nova,openstack/nova,mgagne/nova,takeshineshiro/nova