[PATCH] signal: update outdated comment for removed freezable_schedule()

[Kexin Sun]

The function freezable_schedule() was removed in commit
f5d39b020809 ("freezer,sched: Rewrite core freezer logic"), which
rewrote the freezer to use a dedicated TASK_FROZEN state instead.

do_signal_stop() and ptrace_stop() no longer call
freezable_schedule(); they now set TASK_STOPPED/TASK_TRACED and the
freezer handles those states directly via TASK_FROZEN.  Update the
comment to reflect the current mechanism.

Assisted-by: unnamed:deepseek-v3.2 coccinelle
Signed-off-by: Kexin Sun <kexinsun@xxxxxxxxxxxxxxxx>
---
 kernel/signal.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index d65d0fe24bfb..926fe953a700 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2814,8 +2814,9 @@ bool get_signal(struct ksignal *ksig)
 
 	/*
 	 * Do this once, we can't return to user-mode if freezing() == T.
-	 * do_signal_stop() and ptrace_stop() do freezable_schedule() and
-	 * thus do not need another check after return.
+	 * do_signal_stop() and ptrace_stop() set TASK_STOPPED/TASK_TRACED
+	 * and the freezer handles those states via TASK_FROZEN, thus they
+	 * do not need another check after return.
 	 */
 	try_to_freeze();
 
-- 
2.25.1