Fix -Wunused-variable warning. NFCI.

llvm-svn: 336329
diff --git a/clang-tools-extra/clangd/Quality.cpp b/clang-tools-extra/clangd/Quality.cpp
index 2dd8444..be02365 100644
--- a/clang-tools-extra/clangd/Quality.cpp
+++ b/clang-tools-extra/clangd/Quality.cpp
@@ -198,7 +198,7 @@
     if (R->isInjectedClassName())
       DC = DC->getParent();
   // Class constructor should have the same scope as the class.
-  if (const auto *Ctor = llvm::dyn_cast<CXXConstructorDecl>(D))
+  if (isa<CXXConstructorDecl>(D))
     DC = DC->getParent();
   bool InClass = false;
   for (; !DC->isFileContext(); DC = DC->getParent()) {