KVM: PPC: Fix vcpu_create dereference before validity check.

Fix usage of vcpu struct before check that it's actually valid.
Signed-off-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/powerpc/kvm/powerpc.c

@@ -289,9 +289,10 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
 {
 	struct kvm_vcpu *vcpu;
 	vcpu = kvmppc_core_vcpu_create(kvm, id);
-	vcpu->arch.wqp = &vcpu->wq;
-	if (!IS_ERR(vcpu))
+	if (!IS_ERR(vcpu)) {
+		vcpu->arch.wqp = &vcpu->wq;
 		kvmppc_create_vcpu_debugfs(vcpu, id);
+	}
 	return vcpu;
 }