rtc: pcf2127: use sysfs_emit() instead of sprintf()

Use sysfs_emit() instead of sprintf() in the sysfs show callback
(timestamp_show) to conform to the recommended sysfs attribute
formatting guidelines in Documentation/filesystems/sysfs.rst.

Reviewed-by: Bruno Thomsen <bruno.thomsen@gmail.com>
Link: https://patch.msgid.link/20261029132339.925021-2-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-pcf2127.c

diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
index ff20239..49542cc 100644
--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -972,7 +972,7 @@ static ssize_t timestamp_show(struct device *dev,
 		if (ret)
 			return ret;
 	}
-	return sprintf(buf, "%llu\n", (unsigned long long)ts);
+	return sysfs_emit(buf, "%llu\n", (unsigned long long)ts);
 }
 
 static ssize_t timestamp0_show(struct device *dev,