clocksource/drivers/hyper-v: Make sched clock return nanoseconds correctly

The sched clock read functions return the HV clock (100ns granularity)
without converting it to nanoseconds.

Add the missing conversion.

Fixes: bd00cd52 ("clocksource/drivers/hyperv: Add Hyper-V specific sched clock function")
Signed-off-by: Yubo Xie <yuboxie@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200327021159.31429-1-Tianyu.Lan@microsoft.com

drivers/clocksource/hyperv_timer.c

@@ -343,7 +343,8 @@ static u64 notrace read_hv_clock_tsc_cs(struct clocksource *arg)
 
 static u64 read_hv_sched_clock_tsc(void)
 {
-	return read_hv_clock_tsc() - hv_sched_clock_offset;
+	return (read_hv_clock_tsc() - hv_sched_clock_offset) *
+		(NSEC_PER_SEC / HV_CLOCK_HZ);
 }
 
 static void suspend_hv_clock_tsc(struct clocksource *arg)
@@ -398,7 +399,8 @@ static u64 notrace read_hv_clock_msr_cs(struct clocksource *arg)
 
 static u64 read_hv_sched_clock_msr(void)
 {
-	return read_hv_clock_msr() - hv_sched_clock_offset;
+	return (read_hv_clock_msr() - hv_sched_clock_offset) *
+		(NSEC_PER_SEC / HV_CLOCK_HZ);
 }
 
 static struct clocksource hyperv_cs_msr = {