signal: complete_signal: use __for_each_thread()

do/while_each_thread should be avoided when possible.

Link: https://lkml.kernel.org/r/20230909164537.GA11633@redhat.comSigned-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

kernel/signal.c

@@ -1058,12 +1058,11 @@ static void complete_signal(int sig, struct task_struct *p, enum pid_type type)
 			signal->flags = SIGNAL_GROUP_EXIT;
 			signal->group_exit_code = sig;
 			signal->group_stop_count = 0;
-			t = p;
-			do {
+			__for_each_thread(signal, t) {
 				task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK);
 				sigaddset(&t->pending.signal, SIGKILL);
 				signal_wake_up(t, 1);
-			} while_each_thread(p, t);
+			}
 			return;
 		}
 	}