[PATCH v6 5/7] platform/x86: uniwill-wmi: use devm_blocking_notifier_chain_register()

[Eliav Farber <farbere@amazon.com>]

Replace the blocking_notifier_chain_register() +
devm_add_action_or_reset() pattern with a single call to
devm_blocking_notifier_chain_register(), removing the
devm_uniwill_wmi_unregister_notifier() callback.

Signed-off-by: Eliav Farber <farbere@amazon.com>
Reviewed-by: Armin Wolf <W_Armin@gmx.de>
---
Changes in v6:
- Rebased onto v7.4-rc1. No functional change since v5.
- Armin Wolf's Reviewed-by retained; the code is unchanged since v4,
  when it was given.

devm_uniwill_wmi_register_notifier() is kept rather than having
uniwill-acpi.c call devm_blocking_notifier_chain_register() directly,
because uniwill_wmi_chain_head is static to uniwill-wmi.c and dropping
the wrapper would mean exposing it in uniwill-wmi.h. Discussed with Uwe
Kleine-Koenig on v4.

 drivers/platform/x86/uniwill/uniwill-wmi.c | 17 +++--------------
 1 file changed, 3 insertions(+), 14 deletions(-)

diff --git a/drivers/platform/x86/uniwill/uniwill-wmi.c b/drivers/platform/x86/uniwill/uniwill-wmi.c
index afcbfa4f7552..2ffa29a829ee 100644
--- a/drivers/platform/x86/uniwill/uniwill-wmi.c
+++ b/drivers/platform/x86/uniwill/uniwill-wmi.c
@@ -26,22 +26,11 @@
 
 static BLOCKING_NOTIFIER_HEAD(uniwill_wmi_chain_head);
 
-static void devm_uniwill_wmi_unregister_notifier(void *data)
-{
-	struct notifier_block *nb = data;
-
-	blocking_notifier_chain_unregister(&uniwill_wmi_chain_head, nb);
-}
-
 int devm_uniwill_wmi_register_notifier(struct device *dev, struct notifier_block *nb)
 {
-	int ret;
-
-	ret = blocking_notifier_chain_register(&uniwill_wmi_chain_head, nb);
-	if (ret < 0)
-		return ret;
-
-	return devm_add_action_or_reset(dev, devm_uniwill_wmi_unregister_notifier, nb);
+	return devm_blocking_notifier_chain_register(dev,
+						     &uniwill_wmi_chain_head,
+						     nb);
 }
 
 static void uniwill_wmi_notify(struct wmi_device *wdev, union acpi_object *obj)
-- 
2.47.3