issue with unsetting 'arch' flag

[Alexander Best]

hi there,

i think the following example shows the problem better than a long explanation:

`touch ftest && chflags arch ftest && chflags -vv 0 ftest`.
 ^^non-root     ^^root                ^^non-root

chflags claims to have cleared the 'arch' flag (which should be impossible as
non-root user), but indeed has done nothing.

i've tried the same with 'sappnd' and that works as can be expected.

The issue was confirmed to exist in HEAD (me), stable/8 (pgollucc1, jpaetzel)
and stable/7 (nox).
On stable/6 it does NOT exist (jpaetzel). chflags properly fails with EPERM.

cheers.
alex

-- 
a13x