Merge pull request #3774 from ErnestChen1/switch_default0727

[add] switch default clause

Author: BernardXiong

src/ipc.c

@@ -119,6 +119,9 @@ rt_inline rt_err_t rt_ipc_list_suspend(rt_list_t        *list,
                 rt_list_insert_before(list, &(thread->tlist));
         }
         break;
+
+    default:
+        break;  
     }
 
     return RT_EOK;

src/timer.c

@@ -500,7 +500,10 @@ rt_err_t rt_timer_control(rt_timer_t timer, int cmd, void *arg)
             /*timer is stop*/
             *(rt_tick_t *)arg = RT_TIMER_FLAG_DEACTIVATED;
         }
-        break;    
+        break;
+
+    default:
+        break;
     }
 
     return RT_EOK;