[PATCH] fix unchecked return value in register_disk()

From: "Luiz Fernando N. Capitulino" <lcapitulino@prefeitura.sp.gov.br>
Signed-off-by: Luiz Capitulino <lcapitulino@prefeitura.sp.gov.br>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/partitions/check.c

@@ -367,6 +367,9 @@ void register_disk(struct gendisk *disk)
 		return;
 
 	bdev = bdget_disk(disk, 0);
+	if (!bdev)
+		return;
+
 	if (blkdev_get(bdev, FMODE_READ, 0) < 0)
 		return;
 	state = check_partition(disk, bdev);