Fix docstring for check_dvr_serviceable_ports_on_host
Fix docstring for check_dvr_serviceable_ports_on_host

Docstring for check_dvr_serviceable_ports_on_host has ":return:"
section, but just a head, no explanation body there.

Change-Id: I42d2a7d3c2932adbfbf1247aff7c893b9e6ece11

klmitch/neutron,eayunstack/neutron,sebrandon1/neutron,wolverineav/neutron,MaximNevrov/neutron,mahak/neutron,cloudbase/neutron,noironetworks/neutron,MaximNevrov/neutron,klmitch/neutron,eayunstack/neutron,huntxu/neutron,dims/neutron,openstack/neutron,noironetworks/neutron,sebrandon1/neutron,mahak/neutron,bigswitch/neutron,bigswitch/neutron,huntxu/neutron,igor-toga/local-snat,dims/neutron,openstack/neutron,mahak/neutron,cloudbase/neutron,igor-toga/local-snat,wolverineav/neutron,openstack/neutron