dock: bay: Don't call acpi_walk_namespace() when ACPI is disabled.

Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/bay.c b/drivers/acpi/bay.c
index 26038c2..61b6c5b 100644
--- a/drivers/acpi/bay.c
+++ b/drivers/acpi/bay.c
@@ -377,6 +377,9 @@
 
 	INIT_LIST_HEAD(&drive_bays);
 
+	if (acpi_disabled)
+		return -ENODEV;
+
 	/* look for dockable drive bays */
 	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 		ACPI_UINT32_MAX, find_bay, &bays, NULL);