[PATCH] revert "Optimize sys_times for a single thread process"

This patch reverts 'CONFIG_SMP && thread_group_empty()' optimization in
sys_times().  The reason is that the next patch breaks memory ordering which
is needed for that optimization.

tasklist_lock in sys_times() will be eliminated completely by further patch.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/exit.c

@@ -139,11 +139,7 @@ repeat:
 	ptrace_unlink(p);
 	BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children));
 	__exit_signal(p);
-	/*
-	 * Note that the fastpath in sys_times depends on __exit_signal having
-	 * updated the counters before a task is removed from the tasklist of
-	 * the process by __unhash_process.
-	 */
+
 	__unhash_process(p);
 
 	/*