KVM: SEV: use mutex guard in sev_mem_enc_unregister_region()

				  struct kvm_enc_region *range)

{

	struct enc_region *region;

	int ret;

	/* If kvm is mirroring encryption context it isn't responsible for it */

	if (is_mirroring_enc_context(kvm))

		return -EINVAL;

	mutex_lock(&kvm->lock);

	guard(mutex)(&kvm->lock);

	if (!sev_guest(kvm)) {

		ret = -ENOTTY;

		goto failed;

	}

	if (!sev_guest(kvm))

		return -ENOTTY;

	region = find_enc_region(kvm, range);

	if (!region) {

		ret = -EINVAL;

		goto failed;

	}

	if (!region)

		return -EINVAL;

	sev_writeback_caches(kvm);

	__unregister_enc_region_locked(kvm, region);

	mutex_unlock(&kvm->lock);

	return 0;

failed:

	mutex_unlock(&kvm->lock);

	return ret;

}

int sev_vm_copy_enc_context_from(struct kvm *kvm, unsigned int source_fd)