Track libxml2 API changes.

This function is now deprecated upstream, and their advice is to just
not call it; xmlCleanupParser() will do this stuff anyway.

Test: treehugger
Change-Id: I38a80d1f77c1beb2c1c8088a9e0df3bb0cbd9496
diff --git a/audio/common/all-versions/test/utility/src/ValidateXml.cpp b/audio/common/all-versions/test/utility/src/ValidateXml.cpp
index f111c01..4d6f003 100644
--- a/audio/common/all-versions/test/utility/src/ValidateXml.cpp
+++ b/audio/common/all-versions/test/utility/src/ValidateXml.cpp
@@ -63,11 +63,8 @@
         xmlSetGenericErrorFunc(this, errorCb);
     }
     ~Libxml2Global() {
-        // TODO: check if all those cleanup are needed
         xmlSetGenericErrorFunc(nullptr, nullptr);
-        xmlSchemaCleanupTypes();
         xmlCleanupParser();
-        xmlCleanupThreads();
     }
 
     const std::string& getErrors() { return errors; }