bpf_program__set_<TYPE> functions have been deprecated since libbpf 0.8.
Replace with the equivalent bpf_program__set_type call to avoid a
deprecation warning.

Signed-off-by: Haochen Tong <i@hexchain.org>
Reviewed-by: Zhang Chen <chen.zhang@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>