KVM: PPC: Book3S HV: Fix memory leak in kvm_vm_ioctl_get_htab_fd

We do ctx = kzalloc(sizeof(*ctx), GFP_KERNEL) and then later on call
anon_inode_getfd(), but if that fails we don't free ctx, so that
memory gets leaked.  To fix it, this adds kfree(ctx) in the failure
path.
Signed-off-by: nixiaoming <nixiaoming@huawei.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

arch/powerpc/kvm/book3s_64_mmu_hv.c

@@ -1941,6 +1941,7 @@ int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf)
 	rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY;
 	ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC);
 	if (ret < 0) {
+		kfree(ctx);
 		kvm_put_kvm(kvm);
 		return ret;
 	}