detect: Detecting non-contiguous disks on megacli

On some systems, we have non-contiguous slots like in :
                     info = megacli.pdinfo(ctrl,

[root@ceph01-prv src]# megacli -PdList -aAll | grep -i Slot
Slot Number: 0
Slot Number: 1
Slot Number: 2
Slot Number: 3
Slot Number: 4
Slot Number: 5
Slot Number: 6
Slot Number: 7
Slot Number: 8
Slot Number: 9
Slot Number: 10
Slot Number: 11
Slot Number: 12
Slot Number: 13
Slot Number: 22
Slot Number: 23

The existing code was looking slots up to the number of disks while it should consider the number of slots.