[th/acd-reset-instance-cleanup] l3cfg: on n-acd instance-reset clear also ready ACD state
The n-acd instance gets reset in various cases, for example when the MAC address changes or during errors.
When that happens, we also need to forget all our pending probes, because they would reference to a now-defunct n-acd instance.
When the address is currently in state NM_L3_ACD_ADDR_STATE_READY, we possibly have a pending probe. We need to clean that up. Handle it the same as in the other cases. Yes, this means we forget about that the address was ready. But a reset of the n-acd state is a dramatic event. It warrants some drastic start-over.
Fixes: 9a76b07f ('l3cfg: fix assertion failure')
Related: