Remove ml2 resource extension success logging
Remove ml2 resource extension success logging

This is the cause of a tremendous amount of logs, for no
perceivable gain.  A normal dvr run in the gate shows this debug
message around 120K times, which is way too much.

Closes-Bug: #1489952

Change-Id: I26fca8515d866a7cc1638d07fa33bc04479ae221

igor-toga/local-snat,openstack/neutron,chitr/neutron,vivekanand1101/neutron,mattt416/neutron,jumpojoy/neutron,dhanunjaya/neutron,cloudbase/neutron,takeshineshiro/neutron,JianyuWang/neutron,asgard-lab/neutron,asgard-lab/neutron,jumpojoy/neutron,shahbazn/neutron,yanheven/neutron,cloudbase/neutron,glove747/liberty-neutron,skyddv/neutron,bigswitch/neutron,dims/neutron,SamYaple/neutron,MaximNevrov/neutron,shahbazn/neutron,silenci/neutron,yanheven/neutron,eayunstack/neutron,swdream/neutron,noironetworks/neutron,apporc/neutron,mattt416/neutron,dhanunjaya/neutron,dims/neutron,mmnelemane/neutron,sebrandon1/neutron,bigswitch/neutron,mmnelemane/neutron,openstack/neutron,glove747/liberty-neutron,takeshineshiro/neutron,vivekanand1101/neutron,sasukeh/neutron,SamYaple/neutron,wolverineav/neutron,openstack/neutron,wolverineav/neutron,silenci/neutron,sebrandon1/neutron,mahak/neutron,swdream/neutron,igor-toga/local-snat,MaximNevrov/neutron,apporc/neutron,sasukeh/neutron,mahak/neutron,skyddv/neutron,klmitch/neutron,chitr/neutron,huntxu/neutron,mahak/neutron,eayunstack/neutron,JianyuWang/neutron,noironetworks/neutron,klmitch/neutron,huntxu/neutron