net: ethernet: ti: cpsw: correct .ndo_open error path

It's found while review and probably never happens, but real number
of queues is set per device, and error path should be per device.
So split error path based on usage_count.

Signed-off-by: Ivan Khoronzhuk <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/ti/cpsw.c

···
 	return 0;
 
 err_cleanup:
-	cpdma_ctlr_stop(cpsw->dma);
-	for_each_slave(priv, cpsw_slave_stop, cpsw);
+	if (!cpsw->usage_count) {
+		cpdma_ctlr_stop(cpsw->dma);
+		for_each_slave(priv, cpsw_slave_stop, cpsw);
+	}
+
 	pm_runtime_put_sync(cpsw->dev);
 	netif_carrier_off(priv->ndev);
 	return ret;