Only fetch node once for vif actions
Only fetch node once for vif actions

This removes an unneeded refetching of 'node' from Ironic when plugging
and unplugging vifs.

Change-Id: I0050d956b2df8115540f7cf66a897f8f0c751d56

ionutbalutoiu/ironic,rdo-management/ironic,varunarya10/ironic,dims/ironic,hpproliant/ironic,naototty/vagrant-lxc-ironic,openstack/ironic,rackerlabs/ironic,naterh/ironic,froyobin/ironic,supermari0/ironic,NaohiroTamura/ironic,NaohiroTamura/ironic,bacaldwell/ironic,SauloAislan/ironic,devananda/ironic,SauloAislan/ironic,pshchelo/ironic,Tan0/ironic,pshchelo/ironic,ionutbalutoiu/ironic,faizan-barmawer/openstack_ironic,openstack/ironic,Tehsmash/ironic,debayanray/ironic_backup,ramineni/myironic,redhat-openstack/ironic,dims/ironic,bacaldwell/ironic,JioCloud/ironic,naototty/vagrant-lxc-ironic