nfp: bpf: relocate jump targets just before the load

Don't translate the program assuming it will be loaded at a given
address.  This will be required for sharing programs between ports
of the same NIC, tail calls and subprograms.  It will also make the
jump targets easier to understand when dumping the program to user
space.

Translate the program as if it was going to be loaded at address
zero.  When load happens add the load offset in and set addresses
of special branches.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>