block: use the %pg format specifier in show_partition

Simplify printing the partition name by using the %pg format specifier
that is equivalent to a bdevname call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20210727062518.122108-4-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/genhd.c

@@ -778,7 +778,6 @@ static int show_partition(struct seq_file *seqf, void *v)
 	struct gendisk *sgp = v;
 	struct block_device *part;
 	unsigned long idx;
-	char buf[BDEVNAME_SIZE];
 
 	/* Don't show non-partitionable removeable devices or empty devices */
 	if (!get_capacity(sgp) || (!disk_max_parts(sgp) &&
@@ -791,10 +790,9 @@ static int show_partition(struct seq_file *seqf, void *v)
 	xa_for_each(&sgp->part_tbl, idx, part) {
 		if (!bdev_nr_sectors(part))
 			continue;
-		seq_printf(seqf, "%4d  %7d %10llu %s\n",
+		seq_printf(seqf, "%4d  %7d %10llu %pg\n",
 			   MAJOR(part->bd_dev), MINOR(part->bd_dev),
-			   bdev_nr_sectors(part) >> 1,
-			   disk_name(sgp, part->bd_partno, buf));
+			   bdev_nr_sectors(part) >> 1, part);
 	}
 	rcu_read_unlock();
 	return 0;