Fixing OPENSTACK-770
Fixing OPENSTACK-770

Trying to remove syncronized lock from create, update and delete
operation of port.
Concurrency test results:
Failed before code changes:
http://135.227.220.69/rally-results/failed_create_update_port.html
Passed after code changes:
http://135.227.220.69/rally-results/passed_create_update_port.html

The changes required are just for create_port. But removing lock
from update and delete method as well since the concurrency were
achieved even without that.

Change-Id: Ia80130fe459f3416cb170f01ea08164d66068e4e

naveensan1/nuage-openstack-neutron,nuagenetworks/nuage-openstack-neutron,nuagenetworks/nuage-openstack-neutron,naveensan1/nuage-openstack-neutron