[PATCH] ufs: fsync implementation

Presently ufs doesn't support "fsync", this make some applications unhappy,
for example vim.  This patch fixes this situation.

Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>