clang-tidy: ending namespace comment (#1132)

Signed-off-by: Rosen Penev <rosenp@gmail.com>

taglib/toolkit/tiostream.cpp

@@ -47,7 +47,7 @@ namespace
 
     return wstr;
   }
-}
+} // namespace
 
 FileName::FileName(const wchar_t *name) :
   m_wname(name)