tty: do not check tty_unregister_driver's return value

These drivers check tty_unregister_driver return value. But they don't
handle a failure correctly (they free the driver in any case). So stop
checking tty_unregister_driver return value and remove also the prints.

In the next patch, tty_unregister_driver's return type will be switched
to void.

Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: linux-xtensa@linux-xtensa.org
Cc: Jiri Kosina <jikos@kernel.org>
Cc: David Sterba <dsterba@suse.com>
Reviewed-by: NMax Filippov <jcmvbkbc@gmail.com>
Acked-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210302062214.29627-34-jslaby@suse.czSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/xtensa/platforms/iss/console.c

@@ -171,11 +171,7 @@ static int __init rs_init(void)
 
 static __exit void rs_exit(void)
 {
-	int error;
-
-	if ((error = tty_unregister_driver(serial_driver)))
-		pr_err("ISS_SERIAL: failed to unregister serial driver (%d)\n",
-		       error);
+	tty_unregister_driver(serial_driver);
 	put_tty_driver(serial_driver);
 	tty_port_destroy(&serial_port);
 }

drivers/tty/amiserial.c

@@ -1622,21 +1622,17 @@ static int __init amiga_serial_probe(struct platform_device *pdev)
 
 static int __exit amiga_serial_remove(struct platform_device *pdev)
 {
-	int error;
 	struct serial_state *state = platform_get_drvdata(pdev);
 
 	/* printk("Unloading %s: version %s\n", serial_name, serial_version); */
-	error = tty_unregister_driver(serial_driver);
-	if (error)
-		printk("SERIAL: failed to unregister serial driver (%d)\n",
-		       error);
+	tty_unregister_driver(serial_driver);
 	put_tty_driver(serial_driver);
 	tty_port_destroy(&state->tport);
 
 	free_irq(IRQ_AMIGA_TBE, state);
 	free_irq(IRQ_AMIGA_RBF, state);
 
-	return error;
+	return 0;
 }
 
 static struct platform_driver amiga_serial_driver = {

drivers/tty/ipwireless/tty.c

@@ -596,13 +596,8 @@ int ipwireless_tty_init(void)
 
 void ipwireless_tty_release(void)
 {
-	int ret;
-
-	ret = tty_unregister_driver(ipw_tty_driver);
+	tty_unregister_driver(ipw_tty_driver);
 	put_tty_driver(ipw_tty_driver);
-	if (ret != 0)
-		printk(KERN_ERR IPWIRELESS_PCCARD_NAME
-			": tty_unregister_driver failed with code %d\n", ret);
 }
 
 int ipwireless_tty_is_modem(struct ipw_tty *tty)

drivers/tty/moxa.c

@@ -1118,9 +1118,7 @@ static void __exit moxa_exit(void)
 
 	del_timer_sync(&moxaTimer);
 
-	if (tty_unregister_driver(moxaDriver))
-		printk(KERN_ERR "Couldn't unregister MOXA Intellio family "
-				"serial driver\n");
+	tty_unregister_driver(moxaDriver);
 	put_tty_driver(moxaDriver);
 }
 

drivers/tty/serial/kgdb_nmi.c

@@ -373,9 +373,7 @@ int kgdb_unregister_nmi_console(void)
 	if (ret)
 		return ret;
 
-	ret = tty_unregister_driver(kgdb_nmi_tty_driver);
-	if (ret)
-		return ret;
+	tty_unregister_driver(kgdb_nmi_tty_driver);
 	put_tty_driver(kgdb_nmi_tty_driver);
 
 	return 0;

drivers/tty/synclink_gt.c

@@ -3705,7 +3705,6 @@ static const struct tty_operations ops = {
 
 static void slgt_cleanup(void)
 {
-	int rc;
 	struct slgt_info *info;
 	struct slgt_info *tmp;
 
@@ -3714,9 +3713,7 @@ static void slgt_cleanup(void)
 	if (serial_driver) {
 		for (info=slgt_device_list ; info != NULL ; info=info->next_device)
 			tty_unregister_device(serial_driver, info->line);
-		rc = tty_unregister_driver(serial_driver);
-		if (rc)
-			DBGERR(("tty_unregister_driver error=%d\n", rc));
+		tty_unregister_driver(serial_driver);
 		put_tty_driver(serial_driver);
 	}