sfc: don't warn on successful change of MAC

Fixes: 535a61777f ("sfc: suppress handled MCDI failures when changing the MAC address")
Signed-off-by: Bert Kenward <bkenward@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/sfc/ef10.c

@@ -5734,7 +5734,7 @@ static int efx_ef10_set_mac_address(struct efx_nic *efx)
 		 * MCFW do not support VFs.
 		 */
 		rc = efx_ef10_vport_set_mac_address(efx);
-	} else {
+	} else if (rc) {
 		efx_mcdi_display_error(efx, MC_CMD_VADAPTOR_SET_MAC,
 				       sizeof(inbuf), NULL, 0, rc);
 	}