posix-timers: move the initialization of timer->sigq from send to create path

posix_timer_event() always populates timer->sigq with the same numbers,
move this code into sys_timer_create().

Note that with this patch we can kill it_sigev_signo and it_sigev_value.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: mingo@elte.hu
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

kernel/posix-timers.c

@@ -312,11 +312,6 @@ int posix_timer_event(struct k_itimer *timr, int si_private)
 	 */
 	timr->sigq->info.si_sys_private = si_private;
 
-	timr->sigq->info.si_signo = timr->it_sigev_signo;
-	timr->sigq->info.si_code = SI_TIMER;
-	timr->sigq->info.si_tid = timr->it_id;
-	timr->sigq->info.si_value = timr->it_sigev_value;
-
 	shared = !(timr->it_sigev_notify & SIGEV_THREAD_ID);
 	ret = send_sigqueue(timr->sigq, timr->it_process, shared);
 	/* If we failed to send the signal the timer stops. */
@@ -537,6 +532,11 @@ sys_timer_create(const clockid_t which_clock,
 		get_task_struct(process);
 	}
 
+	new_timer->sigq->info.si_code  = SI_TIMER;
+	new_timer->sigq->info.si_tid   = new_timer->it_id;
+	new_timer->sigq->info.si_signo = new_timer->it_sigev_signo;
+	new_timer->sigq->info.si_value = new_timer->it_sigev_value;
+
 	spin_lock_irq(&current->sighand->siglock);
 	new_timer->it_process = process;
 	list_add(&new_timer->list, &current->signal->posix_timers);