tty: use pr_warn_ratelimited() for deprecated serial flags

Use pr_warn_ratelimited() when warning about deprecated serial flags
instead of open coding.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-5-johan@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/tty_io.c

@@ -2626,9 +2626,6 @@ static int tty_tiocgicount(struct tty_struct *tty, void __user *arg)
 
 static int tty_tiocsserial(struct tty_struct *tty, struct serial_struct __user *ss)
 {
-	static DEFINE_RATELIMIT_STATE(depr_flags,
-			DEFAULT_RATELIMIT_INTERVAL,
-			DEFAULT_RATELIMIT_BURST);
 	char comm[TASK_COMM_LEN];
 	struct serial_struct v;
 	int flags;
@@ -2638,9 +2635,9 @@ static int tty_tiocsserial(struct tty_struct *tty, struct serial_struct __user *
 
 	flags = v.flags & ASYNC_DEPRECATED;
 
-	if (flags && __ratelimit(&depr_flags))
-		pr_warn("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n",
-			__func__, get_task_comm(comm, current), flags);
+	if (flags)
+		pr_warn_ratelimited("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n",
+				__func__, get_task_comm(comm, current), flags);
 	if (!tty->ops->set_serial)
 		return -ENOTTY;
 	return tty->ops->set_serial(tty, &v);
@@ -2841,9 +2838,6 @@ struct serial_struct32 {
 static int compat_tty_tiocsserial(struct tty_struct *tty,
 		struct serial_struct32 __user *ss)
 {
-	static DEFINE_RATELIMIT_STATE(depr_flags,
-			DEFAULT_RATELIMIT_INTERVAL,
-			DEFAULT_RATELIMIT_BURST);
 	char comm[TASK_COMM_LEN];
 	struct serial_struct32 v32;
 	struct serial_struct v;
@@ -2860,9 +2854,9 @@ static int compat_tty_tiocsserial(struct tty_struct *tty,
 
 	flags = v.flags & ASYNC_DEPRECATED;
 
-	if (flags && __ratelimit(&depr_flags))
-		pr_warn("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n",
-			__func__, get_task_comm(comm, current), flags);
+	if (flags)
+		pr_warn_ratelimited("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n",
+				__func__, get_task_comm(comm, current), flags);
 	if (!tty->ops->set_serial)
 		return -ENOTTY;
 	return tty->ops->set_serial(tty, &v);