[AFS]: Adjust the new netdevice scanning code

Adjust the new netdevice scanning code provided by Patrick McHardy:

 (1) Restore the function banner comments that were dropped.

 (2) Rather than using an array size of 6 in some places and an array size of
     ETH_ALEN in others, pass a pointer instead and pass the array size
     through so that we can actually check it.

 (3) Do the buffer fill count check before checking the for_primary_ifa
     condition again.  This permits us to skip that check should maxbufs be
     reached before we run out of interfaces.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

fs/afs/main.c

@@ -54,7 +54,7 @@ static int __init afs_get_client_UUID(void)
 
 	/* read the MAC address of one of the external interfaces and construct
 	 * a UUID from it */
-	ret = afs_get_MAC_address(afs_uuid.node);
+	ret = afs_get_MAC_address(afs_uuid.node, sizeof(afs_uuid.node));
 	if (ret < 0)
 		return ret;