[Clangd] NFC: Fixed comment typo

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@368841 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/clangd/unittests/TweakTesting.h b/clangd/unittests/TweakTesting.h
index f79cd5b..6817e72 100644
--- a/clangd/unittests/TweakTesting.h
+++ b/clangd/unittests/TweakTesting.h
@@ -25,7 +25,7 @@
 //   Header = R"cpp(
 //     namespace foo { template<typename> class X{}; }
 //     using namespace foo;
-//   cpp)";
+//   )cpp";
 //   Context = Function;
 //   EXPECT_THAT(apply("[[auto]] X = foo<int>();"),
 //               "foo<int> X = foo<int();");