KVM: selftests: Don't assume vcpu->id is '0' in xAPIC state test

In xapic_state_test's test_icr(), explicitly skip iterations that would
match vcpu->id instead of assuming vcpu->id is '0', so that IPIs are
are correctly sent to non-existent vCPUs.
Suggested-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/kvm/YyoZr9rXSSMEtdh5@google.comSigned-off-by: Gautam Menghani <gautammenghani201@gmail.com>
Link: https://lore.kernel.org/r/20221017175819.12672-1-gautammenghani201@gmail.com
[sean: massage shortlog and changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>

tools/testing/selftests/kvm/x86_64/xapic_state_test.c

@@ -114,7 +114,9 @@ static void test_icr(struct xapic_vcpu *x)
 	 * vCPUs, not vcpu.id + 1.  Arbitrarily use vector 0xff.
 	 */
 	icr = APIC_INT_ASSERT | 0xff;
-	for (i = vcpu->id + 1; i < 0xff; i++) {
+	for (i = 0; i < 0xff; i++) {
+		if (i == vcpu->id)
+			continue;
 		for (j = 0; j < 8; j++)
 			__test_icr(x, i << (32 + 24) | icr | (j << 8));
 	}