selftests/bpf: De-veth-ize the tc_redirect test case

selftests/bpf: De-veth-ize the tc_redirect test case

[ Upstream commit eee82da79f036bb49ff80d3088b9530e3c2e57eb ]

No functional changes to the test case, but just renaming various functions,
variables, etc, to remove veth part of their name for making it more generic
and reusable later on (e.g. for netkit).

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20231114004220.6495-8-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Stable-dep-of: 177f1d083a19 ("selftests/bpf: Fix the flaky tc_redirect_dtime test")
Signed-off-by: Sasha Levin <sashal@kernel.org>