update the "openstack quota show" command to "cinder quota-show"
update the "openstack quota show" command to "cinder quota-show"

This patch:
 - use "cinder quota-show" to take place of "openstack quota show"
 - To view Block Storage quotas , we shoud use "cinder quota-show"
because the "openstack" command will list the all quotas.
 - make consistence to other commands

Change-Id: Ib5af787b9a664f9415ab5d8663434832e8f5b8a5

openstack/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals