thunderbolt: Replace acpi_bus_get_device()

Replace acpi_bus_get_device() that is going to be dropped with
acpi_fetch_acpi_dev().

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <[e-mail]>
Signed-off-by: Mika Westerberg <[e-mail]>

drivers/thunderbolt/acpi.c

···
 static acpi_status tb_acpi_add_link(acpi_handle handle, u32 level, void *data,
 				    void **return_value)
 {
+	struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
 	struct fwnode_reference_args args;
 	struct fwnode_handle *fwnode;
 	struct tb_nhi *nhi = data;
-	struct acpi_device *adev;
 	struct pci_dev *pdev;
 	struct device *dev;
 	int ret;
 
-	if (acpi_bus_get_device(handle, &adev))
+	if (!adev)
 		return AE_OK;
 
 	fwnode = acpi_fwnode_handle(adev);