i40e: Fix VF driver MAC address configuration

Fix a problem where the 'ip link show' command would display stale
link address information after the link address was set via the 'ip
link set' command.  In addition, fix problem with the user being
allowed to overwrite the administratively set VF MAC address.

Change-Id: I669ed14e55f2b633ef7b456b713632b08468671c
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>