Replace 'os' to 'openstack' for all command example
Replace 'os' to 'openstack' for all command example

Trivial-fix

Change-Id: I670dd1240328859d5f10bb4d4ef878f1c8a0ed69

Juniper/python-neutronclient,huntxu/python-neutronclient,openstack/python-neutronclient,noironetworks/python-neutronclient,noironetworks/python-neutronclient,Juniper/python-neutronclient,huntxu/python-neutronclient,openstack/python-neutronclient