More informative nova-scheduler log after NoValidHost is caught.
More informative nova-scheduler log after NoValidHost is caught.

This patch adds a warning log entry for when a NoValidHost
exception causes a scheduling error. The NoValidHost
exception's message will be logged before reporting that
the machine went to error. Previously, all other exceptions
would show a stack trace. However, since the NoValidHost case
is skipped, a user may not understand why his/her machine
went to an ERROR state. This patch seeks to remove any
confusion.

Change-Id: I0f01b1095251f5c659fe010c7376f3f6bc56babe
Closes-Bug: 1336977

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