[VLAN]: Add two missing checks to vlan_ioctl_handler()

In vlan_ioctl_handler() the code misses couple checks for
error return values.
Signed-off-by: NMika Kukkonen <mikukkon@iki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/8021q/vlan.c

@@ -753,6 +753,8 @@ static int vlan_ioctl_handler(void __user *arg)
 		break;
 	case GET_VLAN_REALDEV_NAME_CMD:
 		err = vlan_dev_get_realdev_name(args.device1, args.u.device2);
+		if (err)
+			goto out;
 		if (copy_to_user(arg, &args,
 				 sizeof(struct vlan_ioctl_args))) {
 			err = -EFAULT;
@@ -761,6 +763,8 @@ static int vlan_ioctl_handler(void __user *arg)
 
 	case GET_VLAN_VID_CMD:
 		err = vlan_dev_get_vid(args.device1, &vid);
+		if (err)
+			goto out;
 		args.u.VID = vid;
 		if (copy_to_user(arg, &args,
 				 sizeof(struct vlan_ioctl_args))) {
@@ -774,7 +778,7 @@ static int vlan_ioctl_handler(void __user *arg)
 			__FUNCTION__, args.cmd);
 		return -EINVAL;
 	};
-
+out:
 	return err;
 }