unregister_netdevice: waiting for netdevsim2 to become free. Usage count = 2
leaked reference.
 __netdev_tracker_alloc include/linux/netdevice.h:4051 [inline]
 netdev_tracker_alloc include/linux/netdevice.h:4063 [inline]
 fib6_nh_init+0x620/0x19cc net/ipv6/route.c:3665
 ip6_route_info_create+0x7b0/0xf7c net/ipv6/route.c:3846
 addrconf_f6i_alloc+0x188/0x330 net/ipv6/route.c:4621
 ipv6_add_addr+0x3b4/0xccc net/ipv6/addrconf.c:1121
 addrconf_add_linklocal+0x22c/0x5d0 net/ipv6/addrconf.c:3261
 addrconf_addr_gen+0x3b4/0x4a8 net/ipv6/addrconf.c:3392
 addrconf_init_auto_addrs+0x628/0x9b0 net/ipv6/addrconf.c:-1
 addrconf_notify+0x8dc/0xca8 net/ipv6/addrconf.c:3688
 notifier_call_chain kernel/notifier.c:87 [inline]
 raw_notifier_call_chain+0xd4/0x164 kernel/notifier.c:455
 call_netdevice_notifiers_info net/core/dev.c:2001 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline]
 call_netdevice_notifiers net/core/dev.c:2053 [inline]
 __dev_notify_flags+0x250/0x46c net/core/dev.c:-1
 dev_change_flags+0xc8/0x154 net/core/dev.c:8702
 do_setlink+0xa24/0x32c4 net/core/rtnetlink.c:2833
 __rtnl_newlink net/core/rtnetlink.c:3608 [inline]
 rtnl_newlink+0x12d0/0x1a1c net/core/rtnetlink.c:3655
 rtnetlink_rcv_msg+0x734/0xce4 net/core/rtnetlink.c:6153
 netlink_rcv_skb+0x208/0x3c4 net/netlink/af_netlink.c:2493
 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:6171
netdevsim netdevsim1 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim1 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0