ASoC: core: Replace sprintf() with sysfs_emit()

For sysfs outputs, it's safer to use a new helper, sysfs_emit(),
instead of the raw sprintf() & co.  This patch replaces the sprintf()
usage straightforwardly with a new helper, sysfs_emit().
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20220801170108.26340-7-tiwai@suse.deSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-core.c

@@ -72,7 +72,7 @@ static ssize_t pmdown_time_show(struct device *dev,
 {
 	struct snd_soc_pcm_runtime *rtd = dev_get_drvdata(dev);
 
-	return sprintf(buf, "%ld\n", rtd->pmdown_time);
+	return sysfs_emit(buf, "%ld\n", rtd->pmdown_time);
 }
 
 static ssize_t pmdown_time_store(struct device *dev,