macsec: let the administrator set UP state even if lowerdev is down

[ Upstream commit 07bddef9839378bd6f95b393cf24c420529b4ef1 ]

Currently, the kernel doesn't let the administrator set a macsec device
up unless its lower device is currently up. This is inconsistent, as a
macsec device that is up won't automatically go down when its lower
device goes down.

Now that linkstate propagation works, there's really no reason for this
limitation, so let's remove it.

Fixes: c09440f7 ("macsec: introduce IEEE 802.1AE driver")
Reported-by: NRadu Rendec <radu.rendec@gmail.com>
Signed-off-by: NSabrina Dubroca <sd@queasysnail.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSasha Levin <sashal@kernel.org>

drivers/net/macsec.c

@@ -2813,9 +2813,6 @@ static int macsec_dev_open(struct net_device *dev)
 	struct net_device *real_dev = macsec->real_dev;
 	int err;
 
-	if (!(real_dev->flags & IFF_UP))
-		return -ENETDOWN;
-
 	err = dev_uc_add(real_dev, dev->dev_addr);
 	if (err < 0)
 		return err;