Revert "iee1275/datetime: Fix off-by-1 error."

This is causing the test grub_cmd_date() to fail because the returned
date is one day more than it should be.

This reverts commit 607d66116 (iee1275/datetime: Fix off-by-1 error.).

Signed-off-by: Glenn Washburn <development@efficientek.com>
Tested-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

grub-core/lib/ieee1275/datetime.c

@@ -95,7 +95,7 @@ grub_get_datetime (struct grub_datetime *datetime)
 
   datetime->year = args.year;
   datetime->month = args.month;
-  datetime->day = args.day + 1;
+  datetime->day = args.day;
   datetime->hour = args.hour;
   datetime->minute = args.minute;
   datetime->second = args.second;
@@ -140,7 +140,7 @@ grub_set_datetime (struct grub_datetime *datetime)
 
   args.year = datetime->year;
   args.month = datetime->month;
-  args.day = datetime->day - 1;
+  args.day = datetime->day;
   args.hour = datetime->hour;
   args.minute = datetime->minute;
   args.second = datetime->second;