ipfix-export: rename variables when building bufs
ipfix-export: rename variables when building bufs

Rename the local variables used when building ipfix export packets to make
it clear that they are v4 specific variables.

Type: improvement
Signed-off-by: Paul Atkins <bd156abe841cbed4bdcc19e9b73d63734967d2c5@graphiant.com>
Change-Id: I3a5a623aeb0b6f2b7fcdafb3fc19c500934c529b

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