[hurd,commited] htl: Add missing fork.h

[Adhemerval Zanella]

On 24/03/2021 09:31, Samuel Thibault wrote:
> Adhemerval Zanella, le mer. 24 mars 2021 09:29:44 -0300, a ecrit:
>> On 23/03/2021 21:20, Samuel Thibault wrote:
>>> 2b47727c68b6 ("posix: Consolidate register-atfork") introduced a fork.h
>>> header to declare the atfork unregister hook, but was missing adding it
>>> for htl.
>>>
>>> This fixes tst-atfork2.
>>
>> Both lowlevellock.h and register-atfork.h are common headers,
>> I think it would be better to just add them to generic fork.h header.
> 
> Ok but perhaps there was a reason why you didn't do it in your commit?

I haven't touched the generic fork.h because I haven't see build
issues on i686-gnu.  Why exactly tst-atfork2 fails without
this includes?