KVM: fix kvm_vcpu_kick build failure on S390

S390's kvm_vcpu_stat does not contain halt_wakeup member.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

virt/kvm/kvm_main.c

@@ -1514,6 +1514,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
 	finish_wait(&vcpu->wq, &wait);
 }
 
+#ifndef CONFIG_S390
 /*
  * Kick a sleeping VCPU, or a guest VCPU in guest mode, into host kernel mode.
  */
@@ -1535,6 +1536,7 @@ void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
 			smp_send_reschedule(cpu);
 	put_cpu();
 }
+#endif /* !CONFIG_S390 */
 
 void kvm_resched(struct kvm_vcpu *vcpu)
 {