[SCSI] qla2xxx: Correct out of bounds read of ISP2200 mailbox registers.

ISP2200 adapters only have 24 mailbox registers so read only that many.
Reported-by: Olatunji Ruwase <oor@cs.cmu.edu>
Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/qla2xxx/qla_def.h

@@ -44,6 +44,7 @@
  * ISP2100 HBAs.
  */
 #define MAILBOX_REGISTER_COUNT_2100	8
+#define MAILBOX_REGISTER_COUNT_2200	24
 #define MAILBOX_REGISTER_COUNT		32
 
 #define QLA2200A_RISC_ROM_VER	4

drivers/scsi/qla2xxx/qla_os.c

@@ -2054,7 +2054,7 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 		ha->nvram_data_off = ~0;
 		ha->isp_ops = &qla2100_isp_ops;
 	} else if (IS_QLA2200(ha)) {
-		ha->mbx_count = MAILBOX_REGISTER_COUNT;
+		ha->mbx_count = MAILBOX_REGISTER_COUNT_2200;
 		req_length = REQUEST_ENTRY_CNT_2200;
 		rsp_length = RESPONSE_ENTRY_CNT_2100;
 		ha->max_loop_id = SNS_LAST_LOOP_ID_2100;