Assign task_struct.exit_code before taskstats_exit()

taskstats.ac_exitcode is assigned to task_struct.exit_code in bacct_add_tsk()
through the following kernel function calls:

  do_exit()
    taskstats_exit()
      fill_pid()
        bacct_add_tsk()

The problem is that in do_exit(), task_struct.exit_code is set to 'code' only
after taskstats_exit() has been called.  So we need to move the assignment
before taskstats_exit().

Signed-off-by: Jonathan Lim <jlim@sgi.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/exit.c

@@ -975,6 +975,7 @@ fastcall NORET_TYPE void do_exit(long code)
 	if (unlikely(tsk->audit_context))
 		audit_free(tsk);
 
+	tsk->exit_code = code;
 	taskstats_exit(tsk, group_dead);
 
 	exit_mm(tsk);
@@ -996,7 +997,6 @@ fastcall NORET_TYPE void do_exit(long code)
 	if (tsk->binfmt)
 		module_put(tsk->binfmt->module);
 
-	tsk->exit_code = code;
 	proc_exit_connector(tsk);
 	exit_task_namespaces(tsk);
 	exit_notify(tsk);