Fix warning about unused variable [NFC]

llvm-svn: 346950
diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp
index 176152a..e4895fe 100644
--- a/clang/lib/CodeGen/CGDecl.cpp
+++ b/clang/lib/CodeGen/CGDecl.cpp
@@ -976,9 +976,9 @@
       return CGM.getMangledName(FD);
     } else if (const auto *OM = dyn_cast<ObjCMethodDecl>(DC)) {
       return OM->getNameAsString();
-    } else if (const auto *OM = dyn_cast<BlockDecl>(DC)) {
+    } else if (isa<BlockDecl>(DC)) {
       return "<block>";
-    } else if (const auto *OM = dyn_cast<CapturedDecl>(DC)) {
+    } else if (isa<CapturedDecl>(DC)) {
       return "<captured>";
     } else {
       llvm::llvm_unreachable_internal("expected a function or method");