scsi: mpi3mr: Fix an issue found by KASAN

Write only correct size (32 instead of 64 bytes).

Link: https://lore.kernel.org/r/20230213193752.6859-1-thenzl@redhat.com


Fixes: 42fc9fee ("scsi: mpi3mr: Add helper functions to manage device's port")
Signed-off-by: Tomas Henzl <thenzl@redhat.com>
Acked-by: Sathya Prakash Veerichetty <sathya.prakash@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>