pktcdvd: use sysfs_emit() to instead of scnprintf()

Follow the advice of the Documentation/filesystems/sysfs.rst and show()
should only use sysfs_emit() or sysfs_emit_at() when formatting the
value to be returned to user space.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230310164549.22133-4-andriy.shevchenko@linux.intel.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/pktcdvd.c

@@ -335,7 +335,7 @@ static ssize_t device_map_show(const struct class *c, const struct class_attribu
 		struct pktcdvd_device *pd = pkt_devs[idx];
 		if (!pd)
 			continue;
-		n += sprintf(data+n, "%s %u:%u %u:%u\n",
+		n += sysfs_emit_at(data, n, "%s %u:%u %u:%u\n",
 			pd->disk->disk_name,
 			MAJOR(pd->pkt_dev), MINOR(pd->pkt_dev),
 			MAJOR(pd->bdev->bd_dev),