ACPI / dock: Use acpi_device_enumerated() to check if dock is present

After commit 202317a (ACPI / scan: Add acpi_device objects for
all device nodes in the namespace) acpi_bus_get_device() will always
return 0 for dock devices in dock_notify(), so the dock station
docking code under ACPI_NOTIFY_DEVICE_CHECK will never be executed
and docking will not work as a result of that.

Fix the problem by making dock_notify() use acpi_device_enumerated()
to check the presence of the device instead of checking the return
value of acpi_bus_get_device().

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

drivers/acpi/dock.c

@@ -609,7 +609,7 @@ static int handle_eject_request(struct dock_station *ds, u32 event)
 static void dock_notify(struct dock_station *ds, u32 event)
 {
 	acpi_handle handle = ds->handle;
-	struct acpi_device *ad;
+	struct acpi_device *adev = NULL;
 	int surprise_removal = 0;
 
 	/*
@@ -632,7 +632,8 @@ static void dock_notify(struct dock_station *ds, u32 event)
 	switch (event) {
 	case ACPI_NOTIFY_BUS_CHECK:
 	case ACPI_NOTIFY_DEVICE_CHECK:
-		if (!dock_in_progress(ds) && acpi_bus_get_device(handle, &ad)) {
+		acpi_bus_get_device(handle, &adev);
+		if (!dock_in_progress(ds) && !acpi_device_enumerated(adev)) {
 			begin_dock(ds);
 			dock(ds);
 			if (!dock_present(ds)) {