bug in unix/System/Posix/Files.hsc

[Simon Marlow]

> In local.glasgow-haskell-users, you wrote:
> > readSymbolicLink is broken, it assumes that readlink(2)=20
> null terminates its
> > result when it doesn't. this causes all sorts of badness.
>=20
> This should fix it, although all my CVS trees are hosed right now
> (now how did I manage to break something in the backup tree?) and I
> can't actually test it:
<patch snipped>

Thanks, I'll check it in.  As you probably guessed, this stuff hasn't
had any testing yet.

Cheers,
	Simon