KVM: PPC: Make wakeups work again for Book3S HV guests

When commit f43fdc15fa ("KVM: PPC: booke: Improve timer register
emulation") factored out some code in arch/powerpc/kvm/powerpc.c
into a new helper function, kvm_vcpu_kick(), an error crept in
which causes Book3s HV guest vcpus to stall.  This fixes it.
On POWER7 machines, guest vcpus are grouped together into virtual
CPU cores that share a single waitqueue, so it's important to use
vcpu->arch.wqp rather than &vcpu->wq.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/powerpc/kvm/powerpc.c

@@ -562,7 +562,7 @@ void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
 	int cpu = vcpu->cpu;
 
 	me = get_cpu();
-	if (waitqueue_active(&vcpu->wq)) {
+	if (waitqueue_active(vcpu->arch.wqp)) {
 		wake_up_interruptible(vcpu->arch.wqp);
 		vcpu->stat.halt_wakeup++;
 	} else if (cpu != me && cpu != -1) {