[PATCH] loop: fix hard sector size

[PATCH] loop: fix hard sector size

From: Ben Slusky <sluskyb@paranoiacs.org>

We need to set the hardsect_size of the loop device to that of the real
device.

The loop device advertises a block size of 1024 even when configured over a
cdrom.

When burning a ext2 on a cd, and mounting it directly, I get:

	blocksize=2048;

when I losetup /dev/loop0 /dev/cdrom, and then try to mount, I get:

blocksize=1024; and then misaligned transfer; this results in not being able
to read the superblock.

The loop device should be changed to export the same blocksize of the
underlying device