This adds doc comments for the two bpf_program pinning functions,
bpf_program__pin() and bpf_program__unpin()
Signed-off-by: NGrant Seltzer <grantseltzer@gmail.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211209232222.541733-1-grantseltzer@gmail.com