libbpf: Support detecting writable tracepoint program

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4H3JT


CVE: NA

---------------------------

Identify writable tracepoint program by section prefix
raw_tracepoint.w/.

The correct way is back-porting from commit ccaf12d6
("libbpf: Support detecting and attaching of writable tracepoint program"),
but the refactoring of libbpf makes it hard, so using the same section
prefix as ccaf12d6 and post a home-made patch instead.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Reviewed-by: Kuohai Xu <xukuohai@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>