selftests: kvm/s390x: use vm_create_barebones()

This function does the same but makes it clearer why one would use
the "____"-prefixed version of vm_create().
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tools/testing/selftests/kvm/s390x/cmma_test.c

@@ -94,11 +94,6 @@ static void guest_dirty_test_data(void)
 	);
 }
 
-static struct kvm_vm *create_vm(void)
-{
-	return ____vm_create(VM_MODE_DEFAULT);
-}
-
 static void create_main_memslot(struct kvm_vm *vm)
 {
 	int i;
@@ -157,7 +152,7 @@ static struct kvm_vm *create_vm_two_memslots(void)
 {
 	struct kvm_vm *vm;
 
-	vm = create_vm();
+	vm = vm_create_barebones();
 
 	create_memslots(vm);
 
@@ -276,7 +271,7 @@ static void assert_exit_was_hypercall(struct kvm_vcpu *vcpu)
 
 static void test_migration_mode(void)
 {
-	struct kvm_vm *vm = create_vm();
+	struct kvm_vm *vm = vm_create_barebones();
 	struct kvm_vcpu *vcpu;
 	u64 orig_psw;
 	int rc;
@@ -670,7 +665,7 @@ struct testdef {
  */
 static int machine_has_cmma(void)
 {
-	struct kvm_vm *vm = create_vm();
+	struct kvm_vm *vm = vm_create_barebones();
 	int r;
 
 	r = !__kvm_has_device_attr(vm->fd, KVM_S390_VM_MEM_CTRL, KVM_S390_VM_MEM_ENABLE_CMMA);