scsi: mpi3mr: Start controller indexing from 0

scsi: mpi3mr: Start controller indexing from 0

[ Upstream commit 0d32014f1e3e7a7adf1583c45387f26b9bb3a49d ]

Instead of displaying the controller index starting from '1' make the
driver display the controller index starting from '0'.

Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Ranjan Kumar <ranjan.kumar@broadcom.com>
Link: https://lore.kernel.org/r/20241110194405.10108-4-ranjan.kumar@broadcom.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>