bpf: Additional tail call for IPvX-only setups
bpf: Additional tail call for IPvX-only setups

When both IPv4 and IPv6 are enabled, we split the to/from-container BPF
programs into two code paths, one for each IP family, to reduce program
size and complexity. Because our existing K8sVerifier test only covers
the IPv4+IPv6 configuration, new complexity and program size issues
sneaked in for the IPvX-only setups.

These new issues occur when to/from-container contain both the initial IP
parsing code and the IPv4 (resp. IPv6---we have one issue per family)
code path. Splitting these programs such that they only contain the
initial IP parsing code is enough to fix these issues.

Signed-off-by: Paul Chaignon <a027184a55211cd23e3f3094f1fdc728df5e0500@cilium.io>

cilium/cilium,tklauser/cilium,tklauser/cilium,tklauser/cilium,michi-covalent/cilium,cilium/cilium,cilium/cilium,cilium/cilium,cilium/cilium,tklauser/cilium,michi-covalent/cilium,michi-covalent/cilium,tklauser/cilium,michi-covalent/cilium,michi-covalent/cilium