Move L3 offset fixing and odata.ip init out of route finding.
Move L3 offset fixing and odata.ip init out of route finding.

Also, assume in the moved code that setting the L3 offset of an ODP packet
to zero always succeeds.

Signed-off-by: Janne Peltonen <184f24496cb678cb2ae7fb0b4232a4cbe2bea47a@nokia.com>
Reviewed-by: Valentin Radulescu <5c0267d222138450b4835b40b746ecdf0117cfc8@enea.com>

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