db: Add @_retry_on_deadlock to service_update()
db: Add @_retry_on_deadlock to service_update()

Add the _retry_on_deadlock decorator to the service_update() method of
nova's sqlalchemy API.  This decorator is scattered throughout the
sqlalchemy API for other methods that may encounter this error.  The
referenced bug report shows a trace from where it occurred on this
method.

Change-Id: I93b370d6457d2e85493be01a62a76404d228a6fa
Closes-bug: #1370191

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