nbd leeaves threads around even when unloaded (5.4.46)

[Enrico Mioso <mrkiko.rs@gmail.com>]

Hello!
I don't know if this is an issue - still... I used nbd via qemu-nbd, and all worked fine.
Now, I unloaded the driver after finishing. But still I can see around a kernel thread:

$ ps ax
    988 ?        I<     0:02 [kworker/u17:0-knbd0-recv]

$ lsmod |grep -i nbd

Is this an issue?

Thanks for the great work!

Enrico