KVM: PPC: Book 3S: Fix error return in kvm_vm_ioctl_create_spapr_tce()

Fix to return error code -ENOMEM from the memory alloc error handling
case instead of 0, as done elsewhere in this function.
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>

arch/powerpc/kvm/book3s_64_vio.c

@@ -171,6 +171,7 @@ long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
 		goto fail;
 	}
 
+	ret = -ENOMEM;
 	stt = kzalloc(sizeof(*stt) + npages * sizeof(struct page *),
 		      GFP_KERNEL);
 	if (!stt)