[clang-format] Fix LanguageKind comments.

[krasimir]

Summary

With the introduction of LK_ObjC, the comment line for LK_Cpp became obsolete.

[djasper]

Looks good. Thanks!

include/clang/Format/Format.h

struct FormatStyle {
   /// \brief Supported languages.
   ///
   /// When stored in a configuration file, specifies the language, that the
   /// configuration targets. When passed to the ``reformat()`` function, enables
   /// syntax features specific to the language.
   enum LanguageKind {
     /// Do not use.
     LK_None,
-    /// Should be used for C, C++, ObjectiveC, ObjectiveC++.
+    /// Should be used for C, C++.
     LK_Cpp,
     /// Should be used for Java.
     LK_Java,
     /// Should be used for JavaScript.
     LK_JavaScript,
-    /// Should be used for ObjC code.
+    /// Should be used for ObjectiveC, ObjectiveC++.
     LK_ObjC,
     /// Should be used for Protocol Buffers
     /// (https://developers.google.com/protocol-buffers/).
     LK_Proto,
     /// Should be used for TableGen code.
     LK_TableGen
   };