Func name resolution is broken on 5.18

[brb]

On 5.18, both PT_REGS_IP(ctx) and bpf_get_func_ip(ctx) return addrs which are +4 compared to 5.17. This breaks IP => func name resolution via /proc/kallsyms.

@YutaroHayakawa found this commit https://github.com/torvalds/linux/commit/7f0059b58f0257d895fafd2f2e3afe3bbdf21e64 which might explain the +4.

To apply the same fix we might need to teach https://github.com/cilium/ebpf how to load the kernel config.