xen: add static initialization of steal_clock op to xen_time_ops

pv_time_ops might be overwritten with xen_time_ops after the
steal_clock operation has been initialized already. To prevent calling
a now uninitialized function pointer add the steal_clock static
initialization to xen_time_ops.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index fd7cd6f..67356d2 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -364,6 +364,7 @@
 
 static const struct pv_time_ops xen_time_ops __initconst = {
 	.sched_clock = xen_clocksource_read,
+	.steal_clock = xen_steal_clock,
 };
 
 static void __init xen_time_init(void)