5a85ab2f56
In order to call callout_destroy for a callout safely, we have to ensure the function of the callout is not running and pending. To do so, we should use callout_halt, not callout_stop. In this case, we need to pass an interlock to callout_halt to wait for the callout complete. And also we make sure that SME_CALLOUT_INITIALIZED is unset before calling callout_halt to prevent the callout from calling callout_schedule. This is the same as what we did in sys/netinet6/mld6.c@1.61. Reviewed by riastradh@.