[clang-format]NFC improve the comment to match the code

Missing from {D114519}

GitOrigin-RevId: d44f2a6db2c71be04a588431a8ffb80d2d9e76f1
diff --git a/lib/Format/TokenAnnotator.cpp b/lib/Format/TokenAnnotator.cpp
index 19f30b5..e6564a3 100644
--- a/lib/Format/TokenAnnotator.cpp
+++ b/lib/Format/TokenAnnotator.cpp
@@ -314,6 +314,7 @@
     //
     // void (*FunctionPointer)(void);
     // void (&FunctionReference)(void);
+    // void (&&FunctionReference)(void);
     // void (^ObjCBlock)(void);
     bool MightBeFunctionType = !Contexts[Contexts.size() - 2].IsExpression;
     bool ProbablyFunctionType =