[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>
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 551db89..d90c158 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -563,7 +563,7 @@
  * use-rtnetlink.c
  */
 extern int afs_get_ipv4_interfaces(struct afs_interface *, size_t, bool);
-extern int afs_get_MAC_address(u8 [6]);
+extern int afs_get_MAC_address(u8 *, size_t);
 
 /*
  * vlclient.c