octeon_ep: ensure octep_get_link_status() successfully before octep_link_up()

octep_get_link_status() can fail because send mbox message failed, then
octep_get_link_status() will return ret less than 0. Excute octep_link_up()
as long as ret is not equal to 0 in octep_open() now. That is not correct.

The value type of link.state is enum octep_ctrl_net_state. Positive value
represents up. Excute octep_link_up() when ret is bigger than 0.

Fixes: 862cd659 ("octeon_ep: Add driver framework and device initialization")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/octeon_ep/octep_main.c

@@ -521,7 +521,7 @@ static int octep_open(struct net_device *netdev)
 	octep_oq_dbell_init(oct);
 
 	ret = octep_get_link_status(oct);
-	if (ret)
+	if (ret > 0)
 		octep_link_up(netdev);
 
 	return 0;