Merge branch 'bpf-libbpf-cleanups'

Merge branch 'bpf-libbpf-cleanups'

Andrii Nakryiko says:

====================
This patch set's main goal is to teach bpf_object__open() (and its variants)
to automatically derive BPF program type/expected attach type from section
names, similarly to how bpf_prog_load() was doing it. This significantly
improves user experience by eliminating yet another
obvious-only-in-the-hindsight surprise, when using libbpf APIs.

There are a bunch of auxiliary clean-ups and improvements. E.g.,
bpf_program__get_type() and bpf_program__get_expected_attach_type() are added
for completeness and symmetry with corresponding setter APIs. Some clean up
and fixes in selftests/bpf are done as well.
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>