fs/buffer: remove comment about hard sectorsize

fs/buffer: remove comment about hard sectorsize

Commit e1defc4ff0cf ("block: Do away with the notion of hardsect_size")
changed hardsect_size to logical block size. The comment on top still
says hardsect_size.

Remove the comment as the code is pretty clear. While we are at it,
format the relevant code.

Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Link: https://lore.kernel.org/20250618075821.111459-1-p.raghav@samsung.com
Reviewed-by: Daniel Gomez <da.gomez@samsung.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>