Only signal input queue not full if it really is not full

thread_pool.c

@@ -159,6 +159,7 @@ static hts_tpool_result *hts_tpool_next_result_locked(hts_tpool_process *q) {
             // Not technically input full, but can guarantee there is
             // room for the input to go somewhere so we still signal.
             // The waiting code will then check the condition again.
+            if (q->n_input < q->qsize)
                 pthread_cond_signal(&q->input_not_full_c);
             if (!q->shutdown)
                 wake_next_worker(q, 1);