remove some warning

api/i_cmdparser.hpp

@@ -42,7 +42,7 @@ class ICmdParserACK {
   }
 
   int32_t *getAck(int index) {
-    if (index < 0 || index >= sizeof(rawdata) / 4) {
+    if (index < 0 || index >= (int32_t)(sizeof(rawdata) / 4)) {
       return nullptr;
     }
     return (int32_t *)rawdata + index;