Corrected destructor loop to clear all pending events

In `equeue_destroy` the external loop was for main events linked
list and internal loop for siblings.
Siblings start was not initialized correctly for each main link

equeue.c

@@ -91,13 +91,15 @@ int equeue_create_inplace(equeue_t *q, size_t size, void *buffer) {
 void equeue_destroy(equeue_t *q) {
     // call destructors on pending events
     for (struct equeue_event *es = q->queue; es; es = es->next) {
-        for (struct equeue_event *e = q->queue; e; e = e->sibling) {
+        for (struct equeue_event *e = es->sibling; e; e = e->sibling) {
             if (e->dtor) {
                 e->dtor(e + 1);
             }
         }
+        if (es->dtor) {
+                es->dtor(es + 1);
+        }
     }
-
     // notify background timer
     if (q->background.update) {
         q->background.update(q->background.timer, -1);