ACPI / dock: Make 'docked' sysfs attribute work as documented

After recent ACPI core changes acpi_bus_get_device() will always
succeed for dock station ACPI device objects, so show_docked()
should not use that function's return value as an indicator of
whether or not the dock device is present.

Make it use acpi_device_enumerated() for this purpose.

Fixes: 202317a5 (ACPI / scan: Add acpi_device objects for all device nodes in the namespace)
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/dock.c

@@ -713,13 +713,11 @@ static acpi_status __init find_dock_devices(acpi_handle handle, u32 lvl,
 static ssize_t show_docked(struct device *dev,
 			   struct device_attribute *attr, char *buf)
 {
-	struct acpi_device *tmp;
-
 	struct dock_station *dock_station = dev->platform_data;
+	struct acpi_device *adev = NULL;
 
-	if (!acpi_bus_get_device(dock_station->handle, &tmp))
-		return snprintf(buf, PAGE_SIZE, "1\n");
-	return snprintf(buf, PAGE_SIZE, "0\n");
+	acpi_bus_get_device(dock_station->handle, &adev);
+	return snprintf(buf, PAGE_SIZE, "%u\n", acpi_device_enumerated(adev));
 }
 static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);