tools/trace: structure function parameter is not supported yet

[tw4452852]

> zig build trace -Dkprobe=ip4_addr_string

src/bpf/args.zig:170:12: error: expected type 'vmlinux.struct_printf_spec', found 'c_ulong'

libbpf did already support this: https://lore.kernel.org/bpf/20220831152652.2078600-1-yhs@fb.com/