ufs: fix parenthesisation in ufs_set_fs_state()

This bug snuck in with

commit 252e211e
Author: Mark Fortescue <mark@mtfhpc.demon.co.uk>
Date:   Tue Oct 16 23:26:31 2007 -0700

    Add in SunOS 4.1.x compatible mode for UFS

Signed-off-by: Roel Kluin <12o3l@tiscali.nl>
Acked-by: Evgeniy Dushistov <dushistov@mail.ru>
Cc: Mark Fortescue <mark@mtfhpc.demon.co.uk>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>