unregister_netdevice: waiting for batadv_slave_0 to become free. Usage count = 2
ref_tracker: netdev@ffff888116502618 has 1/1 users at
     netdev_get_by_index+0x79/0xb0
     fib6_nh_init+0x1cd/0x1ff0
     rtm_new_nexthop+0x38d6/0x8140
     rtnetlink_rcv_msg+0x7cf/0xb70
     netlink_rcv_skb+0x208/0x470
     netlink_unicast+0x82f/0x9e0
     netlink_sendmsg+0x805/0xb30
     __sock_sendmsg+0x21c/0x270
     ____sys_sendmsg+0x505/0x830
     ___sys_sendmsg+0x21f/0x2a0
     __x64_sys_sendmsg+0x19b/0x260
     do_syscall_64+0xfa/0xfa0
     entry_SYSCALL_64_after_hwframe+0x77/0x7f

