libbpf: introduce bpf_prog_detach2()

introduce bpf_prog_detach2() that takes one more argument prog_fd
vs bpf_prog_detach() that takes only attach_fd and type.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>