Fixup MSan embeddertests

fpdfsdk/fpdfxfa/cpdfxfa_document.cpp

Index: fpdfsdk/fpdfxfa/cpdfxfa_document.cpp
diff --git a/fpdfsdk/fpdfxfa/cpdfxfa_document.cpp b/fpdfsdk/fpdfxfa/cpdfxfa_document.cpp
index bd7f931c5970b2d7278bcbafd996a9552a7e2c90..90a762ddf3f0b4759c60e4449badcec683f2ceae 100644
--- a/fpdfsdk/fpdfxfa/cpdfxfa_document.cpp
+++ b/fpdfsdk/fpdfxfa/cpdfxfa_document.cpp
@@ -45,6 +45,9 @@ CPDFXFA_Document::~CPDFXFA_Document() {
 
   if (m_pSDKDoc) {
     m_pSDKDoc->ClearAllFocusedAnnots();
+    // Once we're deleted the SDKDocument will point at a bad underlying
+    // doc so we need to reset it ...
+    m_pSDKDoc->ResetXFADocument();
     m_pSDKDoc = nullptr;
   }