I'm using libbpf and want to make sure I'm properly handling errors. I see that some functions (such as `bpf_map_batch_common`) return error codes using `libbpf_err_errno()`. My understanding is that since libbpf_err_errno() returns -errno, these function calls can just be followed by checking the returned error code. Some functions (such as `bpf_map__pin`) return `libbpf_err(int ret)` which sets errno and returns the error code. In this case, does errno even need to be checked? Why the inconsistency? I'd like to document this, so anything else that you can add on error handling in libbpf is welcome. That includes example usage. Thanks!
