ACPICA: Fix possible dereference of null pointer

Fix dereference of possibly null pointer "Predefined" in the case
where the method is not one of the predefined methods.
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/acpica/nspredef.c

@@ -144,7 +144,7 @@ acpi_ns_check_predefined_names(struct acpi_namespace_node *node,
 
 	pathname = acpi_ns_get_external_pathname(node);
 	if (!pathname) {
-		pathname = ACPI_CAST_PTR(char, predefined->info.name);
+		return AE_OK;	/* Could not get pathname, ignore */
 	}
 
 	/*
@@ -230,10 +230,7 @@ acpi_ns_check_predefined_names(struct acpi_namespace_node *node,
 	}
 
       exit:
-	if (pathname != predefined->info.name) {
 	ACPI_FREE(pathname);
-	}
-
 	return (status);
 }