make git show not display a diff
make git show not display a diff

if the top commit includes actual content, this was being displayed
in the devstack log, which was just confusing. --quiet suppresses
this.

Change-Id: Id52604d3b2b9a1372746120cb5d8d741c35576b7

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