Fix errors when commands return error text rather than data
Fix errors when commands return error text rather than data

I'm looking at you euca2ools

Change-Id: I82bfb8a3ee58fdc54ead6a285c9415593e741892

pczerkas/devstack,CloudServer/devstack,TwinkleChawla/devstack,upadhyay-prashant/devstack,BSJAIN92/OpenStack,herrsechs/devstack,HPCHub/devstack,pacinete/devstack,andrewrothstein/devstack,deepakselvaraj/devstack,vishnugonela/devstack,jamielennox/devstack,richliu/devstack,parul24/devstack,Yuriy-Leonov/devstack,andrewrothstein/devstack,kplus/devstack-moonshot,richliu/devstack,pombredanne/devstack,vsham20/devstack,dtroyer/devstack,srics/devstack,bljgaurav/openstack-test,bswartz/devstack,costingalan/devstack,bq-xiao/devstack,herrsechs/devstack,HPCHub/devstack,pacinete/devstack,LoHChina/devstack,citrix-openstack-build/devstack,yamt/devstack,bq-xiao/devstack,cloudbuilders/devstack,dirkmueller/devstack,vishnugonela/devstack,eshnil2000/devstack,affo/devstack,innodee/openstackk,bswartz/devstack,dtroyer/devstack,Millnert/contrail-devstack,shootstar/devstacktest,sc68cal/devstack,Mahito/devstack,liuquansheng47/devstack,Juniper/devstack,williamthegrey/devstack,eharney/devstack,eharney/devstack,flavio-fernandes/devstack,group-policy/devstack,kplus/devstack-moonshot,atulpatil301/devstack,JioCloud/devstack,wenhuizhang/devstack,costingalan/devstack,tianweizhang/devstack,ozamiatin/devstack,rushiagr/devstack,mc2014/devstack,citrix-openstack-build/devstack,ewindisch/raspi-devstack,samgoon/devstack,sc68cal/devstack,noironetworks/devstack,CloudServer/devstack,olivierlemasle/devstack,rushiagr/devstack,mmasaki/devstack,tianweizhang/devstack,neerja28/Devstack_GlusterFS,noironetworks/devstack,varunarya10/devstack,affo/devstack,mmasaki/devstack,TwinkleChawla/devstack,avvocatodemarchis/devstack,j4/devstack,nuxeh/devstack,mc2014/devstack,nuxeh/devstack,parul24/devstack,ozamiatin/devstack,neerja28/Devstack_GlusterFS,Mahito/devstack,NaokiMiyata/devstack,CiscoSystems/devstack,nawawi/openstack,samgoon/devstack,ewindisch/raspi-devstack,j4/devstack,atulpatil301/devstack,sstrato/devstack,promptworks/devstack,thomasem/devstack,armando-migliaccio/devstack,sequenceiq/devstack,group-policy/devstack,mssumanth/devstack,vsham20/devstack,cloudbuilders/devstack,nawawi/openstack,virtualopensystems/devstack,wenhuizhang/devstack,bljgaurav/openstack-test,sequenceiq/devstack,pczerkas/devstack,flavio-fernandes/devstack,mssumanth/devstack,olivierlemasle/devstack,avvocatodemarchis/devstack,inkerra/devstack,prithivm/branch01,liuquansheng47/devstack,LoHChina/devstack,bigswitch/devstack,openstack-dev/devstack,BSJAIN92/OpenStack,bigswitch/devstack,NaokiMiyata/devstack,thomasem/devstack,prithivm/branch01,varunarya10/devstack,promptworks/devstack,pombredanne/devstack,dirkmueller/devstack,openstack-dev/devstack,upadhyay-prashant/devstack