fixed compiler warnings

esp-link/cgioptiboot.c

@@ -648,6 +648,7 @@ static void ICACHE_FLASH_ATTR optibootUartRecv(char *buf, short length) {
       responseLen -= 2;
     }
     armTimer(PGM_INTERVAL); // reset timer
+    break;
   default:
     break;
   }

esp-link/main.c

@@ -137,6 +137,7 @@ user_rf_cal_sector_set(void) {
   switch (system_get_flash_size_map()) {
   case FLASH_SIZE_4M_MAP_256_256: // 512KB
     sect = 128 - 10; // 0x76000
+    break;
   default:
     sect = 128; // 0x80000
   }

mqtt/mqtt.c

@@ -447,7 +447,6 @@ mqtt_send_message(MQTT_Client* client) {
   // get some details about the message
   uint16_t msg_type = mqtt_get_type(buf->data);
   uint8_t  msg_id = mqtt_get_id(buf->data, buf->filled);
-  msg_id = msg_id;
 #ifdef MQTT_DBG
   os_printf("MQTT: Send type=%s id=%04X len=%d\n", mqtt_msg_type[msg_type], msg_id, buf->filled);
 #if 0