!798 bpf: support BPF_PROG_QUERY for progs attached to sockmap

Merge Pull Request from: @kwb0523 
 
Right now there is no way to query whether BPF programs are
attached to a sockmap or not.

we can use the standard interface in libbpf to query, such as:
bpf_prog_query(mapFd, BPF_SK_SKB_STREAM_PARSER, 0, NULL, ...);
the mapFd is the fd of sockmap. 
 
Link:https://gitee.com/openeuler/kernel/pulls/798

 

Reviewed-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Jialin Zhang <zhangjialin11@huawei.com>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>