kern/43452: sem_close not possible after sem_unlink

[pooka%iki.fi@localhost]

>Number:         43452
>Category:       kern
>Synopsis:       sem_close not possible after sem_unlink
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Jun 10 22:15:00 +0000 2010
>Originator:     Antti Kantee
>Release:        
>Organization:
>Environment:
>Description:
A semaphore for which sem_unlink() is called is supposed to retain
resources until sem_close() is called.  However, sem_close() returns
EINVAL due to sem_unlink() removing evidence of a named semaphore.
>How-To-Repeat:
run tests/lib/semaphore/pthread/t_sem_pth tc unlink:

    unlink: Failed: close unlinked semaphore: Invalid argument

>Fix: