Fix order of calls in update_port
Fix order of calls in update_port

https://review.openstack.org/#/c/196908 introduced some extra logic to
do with DVR to update_port, however it changed the ordering of some of
the calls, this patch ensures that the calls that need to happen before
precommit happen in the right place.

Change-Id: I560100b3be76c616a93bf7d3264675dce6cef732
Closes-Bug: #1475297

neoareslinux/neutron,skyddv/neutron,mattt416/neutron,asgard-lab/neutron,sasukeh/neutron,eayunstack/neutron,JianyuWang/neutron,adelina-t/neutron,watonyweng/neutron,jumpojoy/neutron,apporc/neutron,sasukeh/neutron,cloudbase/neutron,cloudbase/neutron,sebrandon1/neutron,silenci/neutron,chitr/neutron,openstack/neutron,noironetworks/neutron,javaos74/neutron,dhanunjaya/neutron,mmnelemane/neutron,wolverineav/neutron,MaximNevrov/neutron,sebrandon1/neutron,suneeth51/neutron,swdream/neutron,silenci/neutron,mahak/neutron,mattt416/neutron,suneeth51/neutron,vivekanand1101/neutron,huntxu/neutron,shahbazn/neutron,glove747/liberty-neutron,SamYaple/neutron,jumpojoy/neutron,apporc/neutron,openstack/neutron,barnsnake351/neutron,javaos74/neutron,shahbazn/neutron,MaximNevrov/neutron,JianyuWang/neutron,bigswitch/neutron,chitr/neutron,takeshineshiro/neutron,swdream/neutron,asgard-lab/neutron,jacknjzhou/neutron,bigswitch/neutron,klmitch/neutron,wolverineav/neutron,huntxu/neutron,mahak/neutron,yanheven/neutron,jacknjzhou/neutron,dims/neutron,dims/neutron,igor-toga/local-snat,SamYaple/neutron,igor-toga/local-snat,eayunstack/neutron,dhanunjaya/neutron,openstack/neutron,neoareslinux/neutron,watonyweng/neutron,glove747/liberty-neutron,yanheven/neutron,adelina-t/neutron,cisco-openstack/neutron,noironetworks/neutron,takeshineshiro/neutron,mahak/neutron,klmitch/neutron,cisco-openstack/neutron,barnsnake351/neutron,mmnelemane/neutron,vivekanand1101/neutron,skyddv/neutron