qla2xxx: Correct (again) overflow during dump-processing on large-memory ISP23xx parts.

Commit 7b867cf7 ([SCSI] qla2xxx:
Refactor qla data structures) inadvertently reverted
e792121e ([SCSI] qla2xxx: Correct
overflow during dump-processing on large-memory ISP23xx parts.).

Cc: stable@kernel.org
Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>