Cygwin: use NULL security descriptor in InitializeObjectAttributes

Using sec_none{_nih} is just a roundabout way to specify a
NULL SD.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

winsup/cygwin/posix_timer.cc

@@ -306,8 +306,7 @@ timer_tracker::settime (int flags, const itimerspec *new_value,
 	    {
 	      OBJECT_ATTRIBUTES attr;
 
-	      InitializeObjectAttributes (&attr, NULL, 0, NULL,
-					  sec_none_nih.lpSecurityDescriptor);
+	      InitializeObjectAttributes (&attr, NULL, 0, NULL, NULL);
 	      status = NtCreateEvent (&cancel_evt, EVENT_ALL_ACCESS, &attr,
 				      NotificationEvent, FALSE);
 	      if (!NT_SUCCESS (status))