6543 Fix memory leak in uu_avl_pool_destroy

*** 126,135 ****
--- 126,136 ----
          }
          (void) pthread_mutex_lock(&uu_apool_list_lock);
          pp->uap_next->uap_prev = pp->uap_prev;
          pp->uap_prev->uap_next = pp->uap_next;
          (void) pthread_mutex_unlock(&uu_apool_list_lock);
+         (void) pthread_mutex_destroy(&pp->uap_lock);
          pp->uap_prev = NULL;
          pp->uap_next = NULL;
          uu_free(pp);
  }