[ACPI] fix possible acpi thermal leak in failure path

Coverity: #601
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/thermal.c

@@ -942,8 +942,10 @@ acpi_thermal_write_trip_points(struct file *file,
 	memset(limit_string, 0, ACPI_THERMAL_MAX_LIMIT_STR_LEN);
 
 	active = kmalloc(ACPI_THERMAL_MAX_ACTIVE * sizeof(int), GFP_KERNEL);
-	if (!active)
+	if (!active) {
+		kfree(limit_string);
 		return_VALUE(-ENOMEM);
+	}
 
 	if (!tz || (count > ACPI_THERMAL_MAX_LIMIT_STR_LEN - 1)) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid argument\n"));