[include-fixer][find-all-symbols] removed unused const member from YamlReporter to fix build bot failure.

llvm-svn: 270571

clang-tools-extra/include-fixer/find-all-symbols/tool/FindAllSymbolsMain.cpp

@@ -82,8 +82,6 @@ public:
   }
 
 private:
-  // Directory to write yaml files to.
-  const std::string Directory;
   std::map<std::string, std::set<SymbolInfo>> Symbols;
 };