rtc: m41t93: stop validating rtc_time in .read_time

The RTC core is always calling rtc_valid_tm after the read_time callback.
It is not necessary to call it just before returning from the callback.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-m41t93.c

@@ -159,7 +159,7 @@ static int m41t93_get_time(struct device *dev, struct rtc_time *tm)
 		tm->tm_hour, tm->tm_mday,
 		tm->tm_mon, tm->tm_year, tm->tm_wday);
 
-	return ret < 0 ? ret : rtc_valid_tm(tm);
+	return ret;
 }