sysevent_evc_unsubscribe
(void) sysevent_evc_unsubscribe(sysev_evc, sysev_sid);
(void) sysevent_evc_unsubscribe(cip->ci_binding,
err = sysevent_evc_unsubscribe(ihdl->sh_binding, sip->si_sid);
if (sysevent_evc_unsubscribe(ihdl->sh_binding, "invalidsid") ==
(void) sysevent_evc_unsubscribe(ds_evchan, ds_sid_name);
extern int sysevent_evc_unsubscribe(evchan_t *, const char *);