fix unit
fix unit

The unit in document is different to source.
This patch fixes the unit to same as source.

Change-Id: I25df51f8e88976d81bae4f36116b5ea2588f8a23

isyippee/ceilometer,tanglei528/ceilometer,ityaptin/ceilometer,idegtiarov/ceilometer,chungg/aodh,MisterPup/Ceilometer-Juno-Extension,openstack/aodh,pczerkas/aodh,r-mibu/ceilometer,fabian4/ceilometer,MisterPup/Ceilometer-Juno-Extension,redhat-openstack/ceilometer,froyobin/ceilometer,openstack/aodh,NeCTAR-RC/ceilometer,cernops/ceilometer,Juniper/ceilometer,sileht/aodh,maestro-hybrid-cloud/ceilometer,pczerkas/aodh,luogangyi/Ceilometer-oVirt,sileht/aodh,Juniper/ceilometer,mathslinux/ceilometer,openstack/ceilometer,eayunstack/ceilometer,maestro-hybrid-cloud/ceilometer,tanglei528/ceilometer,tanglei528/ceilometer,eayunstack/ceilometer,mathslinux/ceilometer,pkilambi/ceilometer,redhat-openstack/ceilometer,m1093782566/openstack_org_ceilometer,isyippee/ceilometer,froyobin/ceilometer,pkilambi/ceilometer,chungg/aodh,fabian4/ceilometer,r-mibu/ceilometer,NeCTAR-RC/ceilometer,NeCTAR-RC/ceilometer,idegtiarov/ceilometer,m1093782566/openstack_org_ceilometer,cernops/ceilometer,ityaptin/ceilometer,openstack/ceilometer,luogangyi/Ceilometer-oVirt