rtc: Switch to use %ptR

Use %ptR instead of open coded variant to print content of
struct rtc_time in human readable format.

Note, we drop the validation option. This is only used in
a deprecated ABI and is mostly wrong as many RTCs will still be valid
after 2100.

Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
diff --git a/drivers/rtc/hctosys.c b/drivers/rtc/hctosys.c
index e79f2a1..23efbe6 100644
--- a/drivers/rtc/hctosys.c
+++ b/drivers/rtc/hctosys.c
@@ -56,12 +56,8 @@ static int __init rtc_hctosys(void)
 
 	err = do_settimeofday64(&tv64);
 
-	dev_info(rtc->dev.parent,
-		"setting system clock to "
-		"%d-%02d-%02d %02d:%02d:%02d UTC (%lld)\n",
-		tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
-		tm.tm_hour, tm.tm_min, tm.tm_sec,
-		(long long) tv64.tv_sec);
+	dev_info(rtc->dev.parent, "setting system clock to %ptR UTC (%lld)\n",
+		 &tm, (long long)tv64.tv_sec);
 
 err_read:
 	rtc_class_close(rtc);