Trim extra octets after the end of IPv4 packets before output.
Trim extra octets after the end of IPv4 packets before output.

Fixes: #197 Sent Ethernet frames may have extra octets at the end

Signed-off-by: Janne Peltonen <184f24496cb678cb2ae7fb0b4232a4cbe2bea47a@nokia.com>
Reviewed-by: Iulia Florea <72f281c478abbafc15acd0ad49fdcb9c67d4c829@enea.com>

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