ACPI: remove unused acpi_is_child_device()

Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 89c112e..91fed42 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1161,20 +1161,6 @@
 }
 
 static int
-acpi_is_child_device(struct acpi_device *device,
-			int (*matcher)(struct acpi_device *))
-{
-	int result = -ENODEV;
-
-	do {
-		if (ACPI_SUCCESS(matcher(device)))
-			return AE_OK;
-	} while ((device = device->parent));
-
-	return result;
-}
-
-static int
 acpi_add_single_object(struct acpi_device **child,
 		       struct acpi_device *parent, acpi_handle handle, int type,
 			struct acpi_bus_ops *ops)