ACPI: EC: add newline when printing 'ec_event_clearing' module parameter

When I cat acpi module parameter
'/sys/module/acpi/parameters/ec_event_clearing', it displays as follows.
It is better to add a newline for easy reading.

[root@hulk-202 ~]# cat /sys/module/acpi/parameters/ec_event_clearing
query[root@hulk-202 ~]#
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/ec.c

@@ -2059,13 +2059,13 @@ static int param_get_event_clearing(char *buffer,
 {
 	switch (ec_event_clearing) {
 	case ACPI_EC_EVT_TIMING_STATUS:
-		return sprintf(buffer, "status");
+		return sprintf(buffer, "status\n");
 	case ACPI_EC_EVT_TIMING_QUERY:
-		return sprintf(buffer, "query");
+		return sprintf(buffer, "query\n");
 	case ACPI_EC_EVT_TIMING_EVENT:
-		return sprintf(buffer, "event");
+		return sprintf(buffer, "event\n");
 	default:
-		return sprintf(buffer, "invalid");
+		return sprintf(buffer, "invalid\n");
 	}
 	return 0;
 }