NULL noise in fs/super.c:kill_bdev_super()

Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Subrata Modak <subrata@linux.vnet.ibm.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

fs/super.c

@@ -922,7 +922,7 @@ void kill_block_super(struct super_block *sb)
 	struct block_device *bdev = sb->s_bdev;
 	fmode_t mode = sb->s_mode;
 
-	bdev->bd_super = 0;
+	bdev->bd_super = NULL;
 	generic_shutdown_super(sb);
 	sync_blockdev(bdev);
 	close_bdev_exclusive(bdev, mode);