fix: 修复蜂鸣器仅剩一个元素时，鸣响时长错误的问题

app/by_buzzer.c

@@ -25,7 +25,7 @@ void queue_add_element(int element)
 }
 void queue_pop_element(void)
 {
-    memmove(a, &a[1], (queue_long - 1) * sizeof(a[0]));
+    memmove(a, &a[1], (queue_long - 1) * sizeof(a[0])); // FIXME 强迫症震怒，仅移动，未清除原位置上的值
     if (queue_long > 0) {
         queue_long--;
     }
@@ -61,16 +61,19 @@ void by_buzzer_add(uint16_t tone)
 
 void by_buzzer_run(void)
 {
-    if (queue_long != 0) {
+    if (queue_long > 0) {
 
         if (0 == time_out) {
             pwm_init(BUZZER_PIN, a[0], 5000);
             queue_pop_element();
             time_out = BUZZER_TIME;
-        } else {
-            time_out--;
         }
     } else {
-        pwm_set_duty(BUZZER_PIN, 0);
+        if (0 == time_out)
+            pwm_set_duty(BUZZER_PIN, 0);
+    }
+
+    if (time_out) {
+        time_out--;
     }
 }