hook_event_int
SLIST_REMOVE(&hfi->hfi_head, hei, hook_event_int, hei_entry);
struct hook_event_int;
typedef struct hook_event_int *hook_event_token_t;
SLIST_ENTRY(hook_event_int) hei_entry;
SLIST_HEAD(hook_event_int_head, hook_event_int);