devices: remove redundant access in af-packet input
devices: remove redundant access in af-packet input

Type: fix

current_data is set to 0 for each packet in af-packet input node.
It is not required to include it to calculate the headers offset.

Signed-off-by: Mohsin Kazmi <3be96aed1fe21f963e790909e1d3a8e57ce776f2@cisco.com>
Change-Id: I538d8c04e24c758155b3f8d6a1532472ef549459

FDio/vpp,FDio/vpp,chrisy/vpp,chrisy/vpp,FDio/vpp,FDio/vpp,chrisy/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp