xen/events: fifo: use xen_vcpu_id mapping

EVTCHNOP_init_control has vCPU id as a parameter and Xen's idea of
vCPU id should be used. Use the newly introduced xen_vcpu_id mapping
to convert it from Linux's id.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

drivers/xen/events/events_fifo.c

@@ -113,7 +113,7 @@ static int init_control_block(int cpu,
 
 	init_control.control_gfn = virt_to_gfn(control_block);
 	init_control.offset      = 0;
-	init_control.vcpu        = cpu;
+	init_control.vcpu        = xen_vcpu_nr(cpu);
 
 	return HYPERVISOR_event_channel_op(EVTCHNOP_init_control, &init_control);
 }