dsa: Use ether_addr_copy

Use ether_addr_copy instead of memcpy(a, b, ETH_ALEN) to
save some cycles on arm and powerpc.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 29d684e..02c0e17 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -156,7 +156,7 @@
 		dev_uc_del(master, dev->dev_addr);
 
 out:
-	memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
+	ether_addr_copy(dev->dev_addr, addr->sa_data);
 
 	return 0;
 }