malloc-fail: Fix type confusion in xmlSchemaCheckAGPropsCorrect Attribute groups must be marked as containing references also if an OOM error occurred. Otherwise, references won't be resolved, leading to type confusion in xmlSchemaCheckAGPropsCorrect later in the fixup phase. I'm not sure why xmlSchemaFixupComponents is called at all if an error occurred. This has lead to similar issues in the past. On the other hand, continuing in the presence of errors helps when fuzzing. See #344.