selftests/bpf: Adding test for attach id vs prototype mismatch

Adding hack into libbpf so we resolve function into BTF id
specified by KRAVA variable.

Getting trace output from bpf program attached to bpf_test_func:

      test_progs-684     [001] ...11    99.660596: bpf_trace_printk: KRAVA 0000000000000001 0000000000000000

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
3 files changed