selftests/bpf: Make res_spin_lock AA test condition stronger

Let's make sure that we see a EDEADLK and ETIMEDOUT whenever checking
for the AA tests (in case of simple AA and AA after exhausting 31
entries).

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250410170023.2670683-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/progs/res_spin_lock.c

@@ -38,13 +38,14 @@ int res_spin_lock_test(struct __sk_buff *ctx)
 	r = bpf_res_spin_lock(&elem1->lock);
 	if (r)
 		return r;
-	if (!bpf_res_spin_lock(&elem2->lock)) {
+	r = bpf_res_spin_lock(&elem2->lock);
+	if (!r) {
 		bpf_res_spin_unlock(&elem2->lock);
 		bpf_res_spin_unlock(&elem1->lock);
 		return -1;
 	}
 	bpf_res_spin_unlock(&elem1->lock);
-	return 0;
+	return r != -EDEADLK;
 }
 
 SEC("tc")
@@ -124,12 +125,15 @@ int res_spin_lock_test_held_lock_max(struct __sk_buff *ctx)
 	/* Trigger AA, after exhausting entries in the held lock table. This
 	 * time, only the timeout can save us, as AA detection won't succeed.
 	 */
-	if (!bpf_res_spin_lock(locks[34])) {
+	ret = bpf_res_spin_lock(locks[34]);
+	if (!ret) {
 		bpf_res_spin_unlock(locks[34]);
 		ret = 1;
 		goto end;
 	}
 
+	ret = ret != -ETIMEDOUT ? 2 : 0;
+
 end:
 	for (i = i - 1; i >= 0; i--)
 		bpf_res_spin_unlock(locks[i]);