Faster get_attrname in nova/objects/base.py
Faster get_attrname in nova/objects/base.py

get_attrname function is called very very often,
and it's string concatenation method is not fast.

* Changing the string concatenation to a 2 times
  faster + operator instead of the % operator.

Change-Id: I326fd6dda8dd41a90757c69867afd62063231362

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