Merge branch 'bpf, btf: Add DEBUG_INFO_BTF checks for __register_bpf_struct_ops'

Geliang Tang says:

====================
bpf: Add DEBUG_INFO_BTF checks for __register_bpf_struct_ops

This patch set avoids module loading failure when the module
trying to register a struct_ops and the module has its btf section
stripped. This will then work similarly as module kfunc registration in
commit 3de4d22c ("bpf, btf: Warn but return no error for NULL btf from __register_btf_kfunc_id_set()")

v5:
 - drop CONFIG_MODULE_ALLOW_BTF_MISMATCH check as Martin suggested.

v4:
 - add a new patch to fix error checks for btf_get_module_btf.
 - rename the helper to check_btf_kconfigs.

v3:
 - fix this build error:
kernel/bpf/btf.c:7750:11: error: incomplete definition of type 'struct module'

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202402040934.Fph0XeEo-lkp@intel.com/



v2:
 - add register_check_missing_btf helper as Jiri suggested.
====================

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>