Fix cache lock for image not consistent
Fix cache lock for image not consistent

Currently 2 external (file) locks with different name
are created to protect image concurrent access for libvirt driver.
This may lead to image corruption in rare case. This patch change
the lock file name from nova-_var_lib_nova_instances_base_xxxx
to nova-xxxx to make the lock name consistent

Change-Id: I3e60c3bcf456d2392409aa56ba05f4ad8fdc0444
Closes-Bug: #1265452

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