bpf: Allow bpf_get_netns_cookie in BPF_PROG_TYPE_SOCK_OPS

mainline inclusion
from mainline-v6.5-rc3
commit 6cf1770d
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I7NL40
CVE: NA

Reference: https://github.com/torvalds/linux/commit/6cf1770d63dd2d0d0d4048e7b3ee360336c072d9



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

We'd like to be able to identify netns from sockops hooks to
accelerate local process communication form different netns.

Signed-off-by: Xu Liu <liuxu623@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210818105820.91894-2-liuxu623@gmail.com


Signed-off-by: JofDiamonds <kwb0523@163.com>
Reviewed-by: wuchangye <wuchangye@huawei.com>