selftests/bpf: Add bench test to arm64 and s390x denylist

BPF CI fails for arm64 and s390x each with the following result:

  [...]
  All error logs:

  serial_test_kprobe_multi_bench_attach:PASS:get_syms 0 nsec
  serial_test_kprobe_multi_bench_attach:PASS:kprobe_multi_empty__open_and_load 0 nsec
  libbpf: prog 'test_kprobe_empty': failed to attach: Operation not supported
  serial_test_kprobe_multi_bench_attach:FAIL:bpf_program__attach_kprobe_multi_opts unexpected error: -95
  #92      kprobe_multi_bench_attach:FAIL
  [...]

Add the test to the deny list.

Fixes: 5b6c7e5c ("selftests/bpf: Add attach bench test")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

tools/testing/selftests/bpf/DENYLIST.aarch64

@@ -28,6 +28,7 @@ kfree_skb                                        # attach fentry unexpected erro
 kfunc_call/subprog                               # extern (var ksym) 'bpf_prog_active': not found in kernel BTF
 kfunc_call/subprog_lskel                         # skel unexpected error: -2
 kfunc_dynptr_param/dynptr_data_null              # libbpf: prog 'dynptr_data_null': failed to attach: ERROR: strerror_r(-524)=22
+kprobe_multi_bench_attach                        # bpf_program__attach_kprobe_multi_opts unexpected error: -95
 kprobe_multi_test/attach_api_addrs               # bpf_program__attach_kprobe_multi_opts unexpected error: -95
 kprobe_multi_test/attach_api_pattern             # bpf_program__attach_kprobe_multi_opts unexpected error: -95
 kprobe_multi_test/attach_api_syms                # bpf_program__attach_kprobe_multi_opts unexpected error: -95

tools/testing/selftests/bpf/DENYLIST.s390x

@@ -29,6 +29,7 @@ htab_update                              # failed to attach: ERROR: strerror_r(-
 kfree_skb                                # attach fentry unexpected error: -524                                        (trampoline)
 kfunc_call                               # 'bpf_prog_active': not found in kernel BTF                                  (?)
 kfunc_dynptr_param                       # JIT does not support calling kernel function                                (kfunc)
+kprobe_multi_bench_attach                # bpf_program__attach_kprobe_multi_opts unexpected error: -95
 kprobe_multi_test                        # relies on fentry
 ksyms_module                             # test_ksyms_module__open_and_load unexpected error: -9                       (?)
 ksyms_module_libbpf                      # JIT does not support calling kernel function                                (kfunc)