ACPI: button: Tweak acpi_button_remove()

Modify acpi_button_remove() to get the ACPI device object pointer
from button->adev instead of retrieving it with the help of the
ACPI_COMPANION() macro to reduce overhead slightly.

While at it, rename the struct acpi_device pointer variable in
acpi_button_remove() to adev.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/13948466.uLZWGnKmhe@rafael.j.wysocki

Author: rafaeljw

drivers/acpi/button.c

@@ -672,10 +672,10 @@ static int acpi_button_probe(struct platform_device *pdev)
 
 static void acpi_button_remove(struct platform_device *pdev)
 {
-	struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
 	struct acpi_button *button = platform_get_drvdata(pdev);
+	struct acpi_device *adev = button->adev;
 
-	switch (device->device_type) {
+	switch (adev->device_type) {
 	case ACPI_BUS_TYPE_POWER_BUTTON:
 		acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
 						acpi_button_event);
@@ -685,7 +685,7 @@ static void acpi_button_remove(struct platform_device *pdev)
 						acpi_button_event);
 		break;
 	default:
-		acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
+		acpi_remove_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
 					   button->type == ACPI_BUTTON_TYPE_LID ?
 						acpi_lid_notify :
 						acpi_button_notify);