db/api: block_device_mapping_update_or_create()
db/api: block_device_mapping_update_or_create()

It is possible to have same virtual device name. So eliminate old entries
whose entry has same virtual device name.

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