Merge pull request #262 in SW_PON/linux from feature/UGW_SW-20918-tc-extension-for-extmark to xrx500

* commit 'b68fc609bc49e3e2a34958e494237115d7f2b529':
  fixed review comments
  UGW_SW-20918 : Add extmark based classify in u32 filter of linux  Traffic Control system