scsi: mpt3sas: fix an out of bound write

cpu_msix_table is allocated to store online cpus, but pci_irq_get_affinity
may return cpu_possible_mask which is then used to access cpu_msix_table.
That causes bad user experience.  Fix limits access to only online cpus,
I've also added an additional test to protect from an unlikely change in
cpu_online_mask.

[mkp: checkpatch]

Fixes: 1d55abc0 ("scsi: mpt3sas: switch to pci_alloc_irq_vectors")
Signed-off-by: Tomas Henzl <thenzl@redhat.com>
Acked-by: Suganath Prabu Subramani <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/mpt3sas/mpt3sas_base.c

@@ -2410,8 +2410,11 @@ _base_assign_reply_queues(struct MPT3SAS_ADAPTER *ioc)
 				continue;
 			}
 
-			for_each_cpu(cpu, mask)
+			for_each_cpu_and(cpu, mask, cpu_online_mask) {
+				if (cpu >= ioc->cpu_msix_table_sz)
+					break;
 				ioc->cpu_msix_table[cpu] = reply_q->msix_index;
+			}
 		}
 		return;
 	}