char: make misc_deregister a void function

With well over 200+ users of this api, there are a mere 12 users that
actually checked the return value of this function.  And all of them
really didn't do anything with that information as the system or module
was shutting down no matter what.

So stop pretending like it matters, and just return void from
misc_deregister().  If something goes wrong in the call, you will get a
WARNING splat in the syslog so you know how to fix up your driver.
Other than that, there's nothing that can go wrong.

Cc: Alasdair Kergon <agk@redhat.com>
Cc: Neil Brown <neilb@suse.com>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Wim Van Sebroeck <wim@iguana.be>
Cc: Christine Caulfield <ccaulfie@redhat.com>
Cc: David Teigland <teigland@redhat.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Acked-by: Joel Becker <jlbec@evilplan.org>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/watchdog/at91rm9200_wdt.c b/drivers/watchdog/at91rm9200_wdt.c
index 41cecb5..9ba1153 100644
--- a/drivers/watchdog/at91rm9200_wdt.c
+++ b/drivers/watchdog/at91rm9200_wdt.c
@@ -269,9 +269,8 @@
 	if (res)
 		dev_warn(dev, "failed to unregister restart handler\n");
 
-	res = misc_deregister(&at91wdt_miscdev);
-	if (!res)
-		at91wdt_miscdev.parent = NULL;
+	misc_deregister(&at91wdt_miscdev);
+	at91wdt_miscdev.parent = NULL;
 
 	return res;
 }
diff --git a/drivers/watchdog/ks8695_wdt.c b/drivers/watchdog/ks8695_wdt.c
index b7ea39b..1e41818 100644
--- a/drivers/watchdog/ks8695_wdt.c
+++ b/drivers/watchdog/ks8695_wdt.c
@@ -254,13 +254,10 @@
 
 static int ks8695wdt_remove(struct platform_device *pdev)
 {
-	int res;
+	misc_deregister(&ks8695wdt_miscdev);
+	ks8695wdt_miscdev.parent = NULL;
 
-	res = misc_deregister(&ks8695wdt_miscdev);
-	if (!res)
-		ks8695wdt_miscdev.parent = NULL;
-
-	return res;
+	return 0;
 }
 
 static void ks8695wdt_shutdown(struct platform_device *pdev)
diff --git a/drivers/watchdog/ts72xx_wdt.c b/drivers/watchdog/ts72xx_wdt.c
index 119beb7..4b54193 100644
--- a/drivers/watchdog/ts72xx_wdt.c
+++ b/drivers/watchdog/ts72xx_wdt.c
@@ -428,7 +428,8 @@
 
 static int ts72xx_wdt_remove(struct platform_device *pdev)
 {
-	return misc_deregister(&ts72xx_wdt_miscdev);
+	misc_deregister(&ts72xx_wdt_miscdev);
+	return 0;
 }
 
 static struct platform_driver ts72xx_wdt_driver = {