KVM: selftests: Don't set reserved bits for invalid Hyper-V hypercall number

Bits 27 through 31 in Hyper-V hypercall 'control' are reserved (see
HV_HYPERCALL_RSVD0_MASK) but '0xdeadbeef' includes them. This causes
KVM to return HV_STATUS_INVALID_HYPERCALL_INPUT instead of the expected
HV_STATUS_INVALID_HYPERCALL_CODE.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/all/87fsgjol20.fsf@redhat.comSigned-off-by: Sean Christopherson <seanjc@google.com>

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

@@ -508,7 +508,7 @@ static void guest_test_hcalls_access(void)
 		switch (stage) {
 		case 0:
 			feat->eax |= HV_MSR_HYPERCALL_AVAILABLE;
-			hcall->control = 0xdeadbeef;
+			hcall->control = 0xbeef;
 			hcall->expect = HV_STATUS_INVALID_HYPERCALL_CODE;
 			break;