ACPI: ec.c: call acpi_get_name to get node name

acpi_namespace_node is internal struct, it should not be used outside of ACPICA
call acpi_get_name to get node ascii name

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index 30f3ef2..2cbc2c9 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -756,10 +756,15 @@
 acpi_ec_register_query_methods(acpi_handle handle, u32 level,
 			       void *context, void **return_value)
 {
-	struct acpi_namespace_node *node = handle;
+	char node_name[5];
+	struct acpi_buffer buffer = { sizeof(node_name), node_name };
 	struct acpi_ec *ec = context;
 	int value = 0;
-	if (sscanf(node->name.ascii, "_Q%x", &value) == 1) {
+	acpi_status status;
+
+	status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
+
+	if (ACPI_SUCCESS(status) && sscanf(node_name, "_Q%x", &value) == 1) {
 		acpi_ec_add_query_handler(ec, value, handle, NULL, NULL);
 	}
 	return AE_OK;