[VLAN]: Lost rtnl_unlock() in vlan_ioctl()

The SET_VLAN_NAME_TYPE_CMD command w/o CAP_NET_ADMIN capability
doesn't release the rtnl lock.

Signed-off-by: Pavel Emelyanov <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/8021q/vlan.c

···
 	case SET_VLAN_NAME_TYPE_CMD:
 		err = -EPERM;
 		if (!capable(CAP_NET_ADMIN))
-			return -EPERM;
+			break;
 		if ((args.u.name_type >= 0) &&
 		    (args.u.name_type < VLAN_NAME_TYPE_HIGHEST)) {
 			vlan_name_type = args.u.name_type;