power_meter: acpi_device_class "power_meter_resource" too long

acpi_device_class can only be 19 characters and a NULL terminator.

The current code has a buffer overflow in acpi_power_meter_add():
       strcpy(acpi_device_class(device), ACPI_POWER_METER_CLASS);

Signed-off-by: Dan Carpenter <[email protected]>
Cc: Len Brown <[email protected]>
Cc: "Darrick J. Wong" <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Len Brown <[email protected]>
diff --git a/drivers/acpi/power_meter.c b/drivers/acpi/power_meter.c
index e8c32a4..66f6729 100644
--- a/drivers/acpi/power_meter.c
+++ b/drivers/acpi/power_meter.c
@@ -35,7 +35,7 @@
 #define ACPI_POWER_METER_NAME		"power_meter"
 ACPI_MODULE_NAME(ACPI_POWER_METER_NAME);
 #define ACPI_POWER_METER_DEVICE_NAME	"Power Meter"
-#define ACPI_POWER_METER_CLASS		"power_meter_resource"
+#define ACPI_POWER_METER_CLASS		"pwr_meter_resource"
 
 #define NUM_SENSORS			17