net: openvswitch: Release reference to netdev

dev_get_by_name will provide a reference on the netdev. So ensure that
the reference of netdev is released after completed.

Fixes: 2540088b ("net: openvswitch: Check vport netdev name")
Signed-off-by: Jun Gu <jun.gu@easystack.cn>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Link: https://lore.kernel.org/r/20240423073751.52706-1-jun.gu@easystack.cnSigned-off-by: Jakub Kicinski <kuba@kernel.org>

net/openvswitch/vport-netdev.c

@@ -78,12 +78,16 @@ struct vport *ovs_netdev_link(struct vport *vport, const char *name)
 	int err;
 
 	vport->dev = dev_get_by_name(ovs_dp_get_net(vport->dp), name);
+	if (!vport->dev) {
+		err = -ENODEV;
+		goto error_free_vport;
+	}
 	/* Ensure that the device exists and that the provided
 	 * name is not one of its aliases.
 	 */
-	if (!vport->dev || strcmp(name, ovs_vport_name(vport))) {
+	if (strcmp(name, ovs_vport_name(vport))) {
 		err = -ENODEV;
-		goto error_free_vport;
+		goto error_put;
 	}
 	netdev_tracker_alloc(vport->dev, &vport->dev_tracker, GFP_KERNEL);
 	if (vport->dev->flags & IFF_LOOPBACK ||