ethdev: fix port state when stop

[ upstream commit 74b7426 ]

Currently, 'dev_started' is always set to be 0 when dev stop, whether
it succeeded or failed. This is unreasonable and this patch fixed it.

Fixes: 62024eb ("ethdev: change stop operation callback to return int")

Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Ferruh Yigit <ferruh.yigit@xilinx.com>

lib/librte_ethdev/rte_ethdev.c

@@ -1785,8 +1785,9 @@ rte_eth_dev_stop(uint16_t port_id)
 		return 0;
 	}
 
-	dev->data->dev_started = 0;
 	ret = (*dev->dev_ops->dev_stop)(dev);
+	if (ret == 0)
+		dev->data->dev_started = 0;
 	rte_ethdev_trace_stop(port_id, ret);
 
 	return ret;