[PATCH] efi: add comment to avoid future expanding of sysfs systab

[Dave Young]

/sys/firmware/efi/systab shows several different values, it breaks sysfs
one file one value design.  But since there are already userspace tools
depend on it eg. kexec-tools so add code comment to alert future expanding
of this file.

Signed-off-by: Dave Young <dyoung@xxxxxxxxxx>
---
 drivers/firmware/efi/efi.c |    2 ++
 1 file changed, 2 insertions(+)

--- linux-x86.orig/drivers/firmware/efi/efi.c
+++ linux-x86/drivers/firmware/efi/efi.c
@@ -109,6 +109,8 @@ struct kobject *efi_kobj;
 /*
  * Let's not leave out systab information that snuck into
  * the efivars driver
+ * Note, do not add more fields in systab sysfs file as it breaks sysfs
+ * one value per file rule!
  */
 static ssize_t systab_show(struct kobject *kobj,
 			   struct kobj_attribute *attr, char *buf)