ACPI: root-only read protection on /sys/firmware/acpi/tables/*

they were world readable.

Signed-off-by: Len Brown <[e-mail]>

drivers/acpi/system.c

···
 	table_attr->attr.size = 0;
 	table_attr->attr.read = acpi_table_show;
 	table_attr->attr.attr.name = table_attr->name;
-	table_attr->attr.attr.mode = 0444;
+	table_attr->attr.attr.mode = 0400;
 
 	return;
 }