[S390] channel measurement interval display.

Display avg_sample_interval in nanoseconds, like it is documented.
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/cio/cmf.c

@@ -1068,6 +1068,7 @@ cmb_show_avg_sample_interval(struct device *dev, struct device_attribute *attr,
 	if (count) {
 		interval = cmb_data->last_update -
 			cdev->private->cmb_start_time;
+		interval = (interval * 1000) >> 12;
 		interval /= count;
 	} else
 		interval = -1;