KVM: PPC: Do not create debugfs if fail to create vcpu

If fail to create the vcpu, we should not create the debugfs
for it.
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Acked-by: Alexander Graf <agraf@suse.de>
Cc: stable@kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

(Cherry-picked from commit 06056bfb)

arch/powerpc/kvm/powerpc.c

@@ -193,7 +193,8 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
 {
 	struct kvm_vcpu *vcpu;
 	vcpu = kvmppc_core_vcpu_create(kvm, id);
-	kvmppc_create_vcpu_debugfs(vcpu, id);
+	if (!IS_ERR(vcpu))
+		kvmppc_create_vcpu_debugfs(vcpu, id);
 	return vcpu;
 }