Segregate the VSM calls from database calls in N1kv plugin
Segregate the VSM calls from database calls in N1kv plugin

Rearrange the code in such a way that the calls to the VSM are
outside the database session. This avoids DB locks on n1kv tables.

Change-Id: Ic0f0d816cca06a3b03fdd9b58ee7599ddf65473e
Closes-Bug: 1290646

Gitweijie/first_project,openstack/networking-cisco,openstack/networking-cisco,noironetworks/networking-cisco,hareeshpc/networking-cisco,CiscoSystems/networking-cisco,CiscoSystems/networking-cisco,hareeshpc/networking-cisco,Tehsmash/networking-cisco,Gitweijie/first_project,noironetworks/networking-cisco,nikolay-fedotov/networking-cisco,cisco-openstack/networking-cisco,cisco-openstack/networking-cisco,Tehsmash/networking-cisco