Remove unnecessary check if agent object from db is not None
Remove unnecessary check if agent object from db is not None

In create_fip_agent_gw_port_if_not_exists() method in
neutron.db.l3_dvr_db module, there was unnecessary check if
object returned from _get_agent_by_type_and_host() method
is not None or not empty dict.
But in fact this method will always return not empty dict or
raise an AgentNotFoundByTypeHost exception which is already
properly handled.

TrivialFix

Change-Id: I71379e21a307326d6fca5798a588630ed3ff5263

mahak/neutron,mahak/neutron,openstack/neutron,openstack/neutron,mahak/neutron,openstack/neutron