stm32f0: usart: simplify while loop in interrupt handler

source/drivers/usart_console.c

@@ -33,12 +33,7 @@ static void usart_isr(struct usart_console *console)
 	if (!console)
 		return;
 
-	do {
-		reg = USART_ISR(console->dev);
-
-		if (!(reg & USART_ISR_RXNE))
-			continue;
-
+	while (usart_get_flag(console->dev, USART_ISR_RXNE)) {
 		console->recv_buf[console->next] = usart_recv(console->dev);
 
 		if (console->recv_buf[console->next] == '\003')
@@ -48,7 +43,7 @@ static void usart_isr(struct usart_console *console)
 
 		if (i != console->cur)
 			console->next = i;
-	} while (usart_get_flag(console->dev, USART_ISR_RXNE));
+	}
 }
 
 void usart1_isr(void)