posix_timer: Move copy_to_user(created_timer_id) down in timer_create()

According to Oleg Nesterov:
We can move copy_to_user(created_timer_id) down after
"if (timer_event_spec)" block too. (but before CLOCK_DISPATCH(),
of course).

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

kernel/posix-timers.c

@@ -560,11 +560,6 @@ SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,
 	new_timer->it_clock = which_clock;
 	new_timer->it_overrun = -1;
 
-	if (copy_to_user(created_timer_id,
-			 &new_timer_id, sizeof (new_timer_id))) {
-		error = -EFAULT;
-		goto out;
-	}
 	if (timer_event_spec) {
 		if (copy_from_user(&event, timer_event_spec, sizeof (event))) {
 			error = -EFAULT;
@@ -590,6 +585,12 @@ SYSCALL_DEFINE3(timer_create, const clockid_t, which_clock,
 	new_timer->sigq->info.si_tid   = new_timer->it_id;
 	new_timer->sigq->info.si_code  = SI_TIMER;
 
+	if (copy_to_user(created_timer_id,
+			 &new_timer_id, sizeof (new_timer_id))) {
+		error = -EFAULT;
+		goto out;
+	}
+
 	error = CLOCK_DISPATCH(which_clock, timer_create, (new_timer));
 	if (error)
 		goto out;