code cleanup: fix code-in-asserts for NDEBUG

src/libespeak-ng/event.c

 	pthread_mutex_init(&my_mutex, (const pthread_mutexattr_t *)NULL);
 	init();
 
-	assert(-1 != pthread_cond_init(&my_cond_start_is_required, NULL));
-	assert(-1 != pthread_cond_init(&my_cond_stop_is_required, NULL));
-	assert(-1 != pthread_cond_init(&my_cond_stop_is_acknowledged, NULL));
+	int a_status;
+
+	a_status = pthread_cond_init(&my_cond_start_is_required, NULL);
+	assert(-1 != a_status);
+	a_status = pthread_cond_init(&my_cond_stop_is_required, NULL);
+	assert(-1 != a_status);
+	a_status = pthread_cond_init(&my_cond_stop_is_acknowledged, NULL);
+	assert(-1 != a_status);
+	(void)a_status;
 
 	pthread_attr_t a_attrib;
 
 	if (!ts)
 		return;
 
-	assert(gettimeofday(&tv, NULL) != -1);
+	int a_status = gettimeofday(&tv, NULL);
+	assert(a_status != -1);
+	(void)a_status;
 	ts->tv_sec = tv.tv_sec;
 	ts->tv_nsec = tv.tv_usec*1000;
 }

src/libespeak-ng/fifo.c

 	pthread_mutex_init(&my_mutex, (const pthread_mutexattr_t *)NULL);
 	init(0);
 
-	assert(-1 != pthread_cond_init(&my_cond_command_is_running, NULL));
-	assert(-1 != pthread_cond_init(&my_cond_start_is_required, NULL));
-	assert(-1 != pthread_cond_init(&my_cond_stop_is_acknowledged, NULL));
+	int a_status;
+	a_status = pthread_cond_init(&my_cond_command_is_running, NULL);
+	assert(-1 != a_status);
+	a_status = pthread_cond_init(&my_cond_start_is_required, NULL);
+	assert(-1 != a_status);
+	a_status = pthread_cond_init(&my_cond_stop_is_acknowledged, NULL);
+	assert(-1 != a_status);
 
 	pthread_attr_t a_attrib;
 	if (pthread_attr_init(&a_attrib)
 	pthread_attr_destroy(&a_attrib);
 
 	// leave once the thread is actually started
-	assert(-1 != pthread_mutex_lock(&my_mutex));
+	a_status = pthread_mutex_lock(&my_mutex);
+	assert(-1 != a_status);
+	(void)a_status;
 	while (my_stop_is_acknowledged == false) {
 		while ((pthread_cond_wait(&my_cond_stop_is_acknowledged, &my_mutex) == -1) && errno == EINTR)
 			;
 {
 	(void)p; // unused
 
+	int a_status;
+
 	// announce that thread is started
-	assert(-1 != pthread_mutex_lock(&my_mutex));
+	a_status = pthread_mutex_lock(&my_mutex);
+	assert(-1 != a_status);
 	my_stop_is_acknowledged = true;
-	assert(-1 != pthread_cond_signal(&my_cond_stop_is_acknowledged));
-	assert(-1 != pthread_mutex_unlock(&my_mutex));
+	a_status = pthread_cond_signal(&my_cond_stop_is_acknowledged);
+	assert(-1 != a_status);
+	a_status = pthread_mutex_unlock(&my_mutex);
+	assert(-1 != a_status);
 
 	bool look_for_inactivity = false;
 
 		}
 		look_for_inactivity = true;
 
-		int a_status = pthread_mutex_lock(&my_mutex);
+		a_status = pthread_mutex_lock(&my_mutex);
 		assert(!a_status);
 
 		if (!a_start_is_required) {
 
 		my_command_is_running = true;
 
-		assert(-1 != pthread_cond_broadcast(&my_cond_command_is_running));
-		assert(-1 != pthread_mutex_unlock(&my_mutex));
+		a_status = pthread_cond_broadcast(&my_cond_command_is_running);
+		assert(-1 != a_status);
+		a_status = pthread_mutex_unlock(&my_mutex);
+		assert(-1 != a_status);
 
 		while (my_command_is_running && !my_terminate_is_required) {
-			int a_status = pthread_mutex_lock(&my_mutex);
+			a_status = pthread_mutex_lock(&my_mutex);
 			assert(!a_status);
 			t_espeak_command *a_command = (t_espeak_command *)pop();
 
 			// and waiting for my_cond_stop_is_acknowledged
 			init(1);
 
-			assert(-1 != pthread_mutex_lock(&my_mutex));
+			a_status = pthread_mutex_lock(&my_mutex);
+			assert(-1 != a_status);
 			my_start_is_required = false;
 
 			// acknowledge the stop request
 			my_stop_is_acknowledged = true;
-			int a_status = pthread_cond_signal(&my_cond_stop_is_acknowledged);
+			a_status = pthread_cond_signal(&my_cond_stop_is_acknowledged);
 			assert(a_status != -1);
 			pthread_mutex_unlock(&my_mutex);
 
 		}
 		// and wait for the next start
 	}
+	(void)a_status;
 
 	return NULL;
 }