"The DISK-SUBSYSTEM is a special model name returned when LUs
are not installed. For example, when LU#0 is not installed in "OPEN-"
models, LU#0 is detected as the DISK-SUBSYSTEM model":
https://marc.info/?l=linux-scsi&m=125424006417825

It's missing for HP XP rebranded arrays, "HP"/"OPEN-".
Only the HITACHI one is present:
13f7e5ac
627511e3

Cc: Anthony Cheung <anthony.cheung@hpe.com>
Cc: Takahiro Yasui <takahiro.yasui@hitachivantara.com>
Cc: Matthias Rudolph <Matthias.Rudolph@hitachivantara.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: James E.J. Bottomley <jejb@linux.vnet.ibm.com>
Cc: SCSI ML <linux-scsi@vger.kernel.org>
Signed-off-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>