unregister_netdevice: waiting for wpan4 to become free. Usage count = 2
leaked reference.
 __netdev_tracker_alloc include/linux/netdevice.h:4070 [inline]
 netdev_hold include/linux/netdevice.h:4099 [inline]
 dev_ifsioc+0xbc0/0xeb0 net/core/dev_ioctl.c:408
 dev_ioctl+0x250/0x1090 net/core/dev_ioctl.c:605
 sock_do_ioctl+0x15a/0x230 net/socket.c:1215
 sock_ioctl+0x1f8/0x680 net/socket.c:1318
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x197/0x210 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd