net/mlx5e: Fix error return code in mlx5e_tc_esw_init()

Fix to return negative error code from the mlx5e_tc_tun_init() error
handling case instead of 0, as done elsewhere in this function.

This commit also using 0 instead of 'ret' when success since it is
always equal to 0.

Fixes: 8914add2 ("net/mlx5e: Handle FIB events to update tunnel endpoint device")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/en_tc.c

@@ -4750,10 +4750,12 @@ int mlx5e_tc_esw_init(struct rhashtable *tc_ht)
 	lockdep_set_class(&tc_ht->mutex, &tc_ht_lock_key);
 
 	uplink_priv->encap = mlx5e_tc_tun_init(priv);
-	if (IS_ERR(uplink_priv->encap))
+	if (IS_ERR(uplink_priv->encap)) {
+		err = PTR_ERR(uplink_priv->encap);
 		goto err_register_fib_notifier;
+	}
 
-	return err;
+	return 0;
 
 err_register_fib_notifier:
 	rhashtable_destroy(tc_ht);