[PATCH] ufs: restore back support of openstep

This is a fix of regression, which triggered by ~2.6.16.

Patch with name ufs-directory-and-page-cache-from-blocks-to-pages.patch: in
additional to conversation from block to page cache mechanism added new
checks of directory integrity, one of them that directory entry do not
across directory chunks.

But some kinds of UFS: OpenStep UFS and Apple UFS (looks like these are the
same filesystems) have different directory chunk size, then common
UFSes(BSD and Solaris UFS).

So this patch adds ability to works with variable size of directory chunks,
and set it for ufstype=openstep to right size.

Tested on darwin ufs.

Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>