selftests/bpf: Fix kprobe_multi_test/attach_override test

We need to deny the attach_override test for arm64, denying the
whole kprobe_multi_test suite. Also making attach_override static.

Fixes: 7182e564 ("selftests/bpf: Add kprobe_multi override test")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230913114711.499829-1-jolsa@kernel.org

tools/testing/selftests/bpf/DENYLIST.aarch64

 bpf_cookie/multi_kprobe_attach_api               # kprobe_multi_link_api_subtest:FAIL:fentry_raw_skel_load unexpected error: -3
 bpf_cookie/multi_kprobe_link_api                 # kprobe_multi_link_api_subtest:FAIL:fentry_raw_skel_load unexpected error: -3
 fexit_sleep                                      # The test never returns. The remaining tests cannot start.
-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
-kprobe_multi_test/bench_attach                   # bpf_program__attach_kprobe_multi_opts unexpected error: -95
-kprobe_multi_test/link_api_addrs                 # link_fd unexpected link_fd: actual -95 < expected 0
-kprobe_multi_test/link_api_syms                  # link_fd unexpected link_fd: actual -95 < expected 0
-kprobe_multi_test/skel_api                       # libbpf: failed to load BPF skeleton 'kprobe_multi': -3
+kprobe_multi_bench_attach                        # needs CONFIG_FPROBE
+kprobe_multi_test                                # needs CONFIG_FPROBE
 module_attach                                    # prog 'kprobe_multi': failed to auto-attach: -95
 fentry_test/fentry_many_args                     # fentry_many_args:FAIL:fentry_many_args_attach unexpected error: -524
 fexit_test/fexit_many_args                       # fexit_many_args:FAIL:fexit_many_args_attach unexpected error: -524

tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c

@@ -454,7 +454,7 @@ static void test_kprobe_multi_bench_attach(bool kernel)
 	}
 }
 
-void test_attach_override(void)
+static void test_attach_override(void)
 {
 	struct kprobe_multi_override *skel = NULL;
 	struct bpf_link *link = NULL;