Remove reduntant call to update_instance_info_cache
Remove reduntant call to update_instance_info_cache

get_instance_nw_info calls _get_instance_nw_info,
which is decorated with @refresh_cache. This in
turn calls update_instance_info_cache, again. This
is both expensive and more importantly dangerous because
the method update_instance_info_cache may call
_get_instance_nw_info itself, thus causing an infinite
loop.

Change-Id: Id8f0241d1c6609cf4e064ee6855228ae7de250e2
Partial-bug: 1235435

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