selftests/bpf: Add cookies check for tracing fill_link_info test

Adding tests for getting cookie with fill_link_info for tracing.

Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250606165818.3394397-2-chen.dylane@linux.dev
1 file changed