[VirtualFileSystem] Fix uninitialized variable warning. NFCI.

llvm-svn: 361371
diff --git a/llvm/lib/Support/VirtualFileSystem.cpp b/llvm/lib/Support/VirtualFileSystem.cpp
index f5a8a1e..48ce314 100644
--- a/llvm/lib/Support/VirtualFileSystem.cpp
+++ b/llvm/lib/Support/VirtualFileSystem.cpp
@@ -1279,7 +1279,7 @@
         EntryArrayContents;
     std::string ExternalContentsPath;
     std::string Name;
-    yaml::Node *NameValueNode;
+    yaml::Node *NameValueNode = nullptr;
     auto UseExternalName =
         RedirectingFileSystem::RedirectingFileEntry::NK_NotSet;
     RedirectingFileSystem::EntryKind Kind;