block: always set bdev->bd_part

Till now, bdev->bd_part is set only if the bdev was for parts other
than part0.  This patch makes bdev->bd_part always set so that code
paths don't have to differenciate common handling.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index f0f6049..87298c0 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -134,12 +134,7 @@
 
 const char *bdevname(struct block_device *bdev, char *buf)
 {
-	int partno = 0;
-
-	if (bdev->bd_part)
-		partno = bdev->bd_part->partno;
-
-	return disk_name(bdev->bd_disk, partno, buf);
+	return disk_name(bdev->bd_disk, bdev->bd_part->partno, buf);
 }
 
 EXPORT_SYMBOL(bdevname);