fix

qirt.c

@@ -326,8 +326,11 @@ static qi_linkedlist_t *qi_linkedlist_push(qi_linkedlist_t *prev, uint64_t i)
 
 static void qi_linkedlist_delete(qi_linkedlist_t *ll)
 {
-  ll->prev->next = ll->next;
-  ll->next->prev = ll->prev;
+  if (ll->prev)
+    ll->prev->next = ll->next;
+
+  if (ll->next)
+    ll->next->prev = ll->prev;
 
   qi_free(ll);
 }