Currently when PF administratively sets VF's MAC address and the VF
is put down (VF tries to delete all MACs) then the MAC is removed
from MAC filters and primary VF MAC is zeroed.

Do not allow untrusted VF to remove primary MAC when it was set
administratively by PF.

Reproducer:
1) Create VF
2) Set VF interface up
3) Administratively set the VF's MAC
4) Put VF interface down

[root@host ~]# echo 1 > /sys/class/net/enp2s0f0/device/sriov_numvfs
[root@host ~]# ip link set enp2s0f0v0 up
[root@host ~]# ip link set enp2s0f0 vf 0 mac fe:6c:b5:da:c7:7d
[root@host ~]# ip link show enp2s0f0
23: enp2s0f0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
    link/ether 3c:ec:ef:b7:dd:04 brd ff:ff:ff:ff:ff:ff
    vf 0     link/ether fe:6c:b5:da:c7:7d brd ff:ff:ff:ff:ff:ff, spoof checking on, link-state auto, trust off
[root@host ~]# ip link set enp2s0f0v0 down
[root@host ~]# ip link show enp2s0f0
23: enp2s0f0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
    link/ether 3c:ec:ef:b7:dd:04 brd ff:ff:ff:ff:ff:ff
    vf 0     link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff, spoof checking on, link-state auto, trust off

Fixes: 700bbf6c ("i40e: allow VF to remove any MAC filter")
Fixes: ceb29474 ("i40e: Add support for VF to specify its primary MAC address")
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://lore.kernel.org/r/20240208180335.1844996-1-anthony.l.nguyen@intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>