sfc: Store MAC address from NVRAM in net_device::perm_addr

For some reason we failed to make this change when perm_addr was
introduced.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/sfc/siena.c b/drivers/net/sfc/siena.c
index b315980..bf84561 100644
--- a/drivers/net/sfc/siena.c
+++ b/drivers/net/sfc/siena.c
@@ -194,13 +194,7 @@
 
 static int siena_probe_nvconfig(struct efx_nic *efx)
 {
-	int rc;
-
-	rc = efx_mcdi_get_board_cfg(efx, efx->mac_address, NULL);
-	if (rc)
-		return rc;
-
-	return 0;
+	return efx_mcdi_get_board_cfg(efx, efx->net_dev->perm_addr, NULL);
 }
 
 static int siena_probe_nic(struct efx_nic *efx)