Fix oversight in container format handling
Fix oversight in container format handling

https://review.openstack.org/5934 changed the container and disk format handling,
but I forgot to reset the variables at the top of the loop (DOH!)

Change-Id: I2782c06e7b4da1b69ecb72f847a5593bda522b7d

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