Merge branch 'bpf-fsession-support-for-s390'

Menglong Dong says:

====================
bpf: fsession support for s390

Implement bpf fsession for the s390 architecture.

Changes v2 -> v1:
* keep LGHI as it was in the 1st patch
* fix up the comment style
* remove the unnecessary checking of fentry->nr_links and fexit->nr_links
  in the 2nd patch
* v1: https://lore.kernel.org/bpf/20260223084022.653186-1-dongml2@chinatelecom.cn/
====================

Link: https://patch.msgid.link/20260224092208.1395085-1-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>