Migrate to the new APIs in clang-r522817

Test: presubmit
Bug: 322868540
Change-Id: I12d80f99e250311f21b202759864b27dfa5253f0
diff --git a/tools/versioner/src/DeclarationDatabase.cpp b/tools/versioner/src/DeclarationDatabase.cpp
index a029c3b..9794286 100644
--- a/tools/versioner/src/DeclarationDatabase.cpp
+++ b/tools/versioner/src/DeclarationDatabase.cpp
@@ -103,7 +103,7 @@
     }
 
     std::string declaration_name = getDeclName(named_decl);
-    bool is_extern = named_decl->getFormalLinkage() == ExternalLinkage;
+    bool is_extern = named_decl->getFormalLinkage() == Linkage::External;
     bool is_definition = false;
     bool no_guard = false;
     bool fortify_inline = false;