Merge pull request #2889 from SummerGGift/master710

[components][serial] 去除串口 DMA 中无法触发的代码判断

components/drivers/serial/serial.c

@@ -428,12 +428,10 @@ static void rt_dma_recv_update_put_index(struct rt_serial_device *serial, rt_siz
         }
     }
     
-    if(rx_fifo->is_full == RT_TRUE) 
+    if(rx_fifo->is_full == RT_TRUE)
     {
-        rx_fifo->get_index = rx_fifo->put_index; 
-    } 
-    
-    if (rx_fifo->get_index >= serial->config.bufsz) rx_fifo->get_index = 0;
+        rx_fifo->get_index = rx_fifo->put_index;
+    }
 }
 
 /*