time: Clean up direct xtime usage in xen

Cleanup xen's direct use of internal timekeeping values.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Acked-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/xen/time.c

@@ -475,6 +475,7 @@ void xen_timer_resume(void)
 __init void xen_time_init(void)
 {
 	int cpu = smp_processor_id();
+	struct timespec tp;
 
 	clocksource_register(&xen_clocksource);
 
@@ -486,9 +487,8 @@ __init void xen_time_init(void)
 	}
 
 	/* Set initial system time with full resolution */
-	xen_read_wallclock(&xtime);
-	set_normalized_timespec(&wall_to_monotonic,
-				-xtime.tv_sec, -xtime.tv_nsec);
+	xen_read_wallclock(&tp);
+	do_settimeofday(&tp);
 
 	setup_force_cpu_cap(X86_FEATURE_TSC);