ACPI / hotplug / PCI: Simplify acpi_install_hotplug_notify_handler()

Since acpi_hotplug_notify_cb() does not use its data argument any
more, the second argument of acpi_install_hotplug_notify_handler()
can be dropped, so do that and update its callers accordingly.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/scan.c

@@ -577,10 +577,10 @@ static void acpi_hotplug_notify_cb(acpi_handle handle, u32 type, void *data)
 	acpi_evaluate_hotplug_ost(handle, type, ost_code, NULL);
 }
 
-void acpi_install_hotplug_notify_handler(acpi_handle handle, void *data)
+void acpi_install_hotplug_notify_handler(acpi_handle handle)
 {
 	acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
-				    acpi_hotplug_notify_cb, data);
+				    acpi_hotplug_notify_cb, NULL);
 }
 
 void acpi_remove_hotplug_notify_handler(acpi_handle handle)
@@ -2040,7 +2040,7 @@ static void acpi_scan_init_hotplug(struct acpi_device *adev)
 		if (!handler)
 			continue;
 
-		acpi_install_hotplug_notify_handler(adev->handle, handler);
+		acpi_install_hotplug_notify_handler(adev->handle);
 		adev->flags.hotplug_notify = true;
 		break;
 	}

drivers/pci/hotplug/acpiphp_glue.c

@@ -376,7 +376,7 @@ static acpi_status register_slot(acpi_handle handle, u32 lvl, void *data,
 
 	/* install notify handler */
 	if (!(newfunc->flags & FUNC_HAS_DCK))
-		acpi_install_hotplug_notify_handler(handle, NULL);
+		acpi_install_hotplug_notify_handler(handle);
 
 	return AE_OK;
 }

include/acpi/acpi_bus.h

@@ -446,7 +446,7 @@ static inline bool acpi_device_enumerated(struct acpi_device *adev)
 typedef void (*acpi_hp_callback)(void *data, u32 src);
 
 acpi_status acpi_hotplug_execute(acpi_hp_callback func, void *data, u32 src);
-void acpi_install_hotplug_notify_handler(acpi_handle handle, void *data);
+void acpi_install_hotplug_notify_handler(acpi_handle handle);
 void acpi_remove_hotplug_notify_handler(acpi_handle handle);
 
 /**