rtc: rx4581: remove useless message

It is not necessary to print a message when the time is invalid as
userspace will already get an error (and an optional dev_dbg message).
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-rx4581.c

@@ -172,11 +172,7 @@ static int rx4581_get_datetime(struct device *dev, struct rtc_time *tm)
 		tm->tm_sec, tm->tm_min, tm->tm_hour,
 		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 
-	err = rtc_valid_tm(tm);
-	if (err < 0)
-		dev_err(dev, "retrieved date/time is not valid.\n");
-
-	return err;
+	return 0;
 }
 
 static int rx4581_set_datetime(struct device *dev, struct rtc_time *tm)