Reported and tested by: Aleš Nesrsta.
* disk/ata.c (grub_atapi_close): Removed. All users updated.
(grub_atapi_dev): Changed .name to "ata". New field .id.
* disk/usbms.c (grub_usbms_close): Removed. All users updated.
(grub_usbms_dev): New field .id.
* disk/scsi.c (grub_scsi_iterate): Generate name.
(grub_scsi_open): Parse name.
* include/grub/scsi.h (grub_make_scsi_id): New function.
(grub_scsi_dev): Change iterate and open to number instead of naming
busses. All users updated.
(grub_scsi): Remove name. Add .bus.