selftests/bpf: Add selftest for attaching tracing programs to functions in deny list

The result:

 $ tools/testing/selftests/bpf/test_progs -t tracing_failure/tracing_deny
 #468/3   tracing_failure/tracing_deny:OK
 #468     tracing_failure:OK
 Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: KaFai Wan <kafai.wan@linux.dev>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20250724151454.499040-4-kafai.wan@linux.dev


Signed-off-by: Alexei Starovoitov <ast@kernel.org>