Interface structures added to and removed from an element list are centralized.
Interface structures added to and removed from an element list are centralized.

Signed-off-by: Hannu Jokinen <cb7811d6e4f31e21756019d681ad07ec7833e91d@nokia.com>
Reviewed-by: Sorin Vultureanu <8013ba55f8675034bc2ab0d6c3a1c9650437ca36@enea.com>

TolikH/ofp,OpenFastPath/ofp,OpenFastPath/ofp,TolikH/ofp,OpenFastPath/ofp,TolikH/ofp,OpenFastPath/ofp