canbuswatchdog forces interfaces up even when brought down intentionally

[rzblue]

Attempting to bring an interface down intentionally (ie, ip link set can_s0 down) will result in canbuswatchdog immediately bringing it back up.

[Kevin-OConnor]

Is there a use case where we expect the bus to be brought down and not restarted?

[rzblue]

Interface parameters can't be changed with the bus up. Perhaps not something users will typically be doing, but needing to disable the restart service makes debugging/development annoying.