mptsas: fix depth param in scsi_track_queue_full

A user of scsi_track_queue_full should pass to the function a constant value
untill the queue-depth changes, otherwise the internal logic in
scsi_track_queue_full rejects the change.  Other users of this function use a
'sdev->queue_depth - 1' as depth parameter, let's do the same.

Signed-off-by: Tomas Henzl <thenzl@redhat.com>
Acked-by: "Sreekanth Reddy" <Sreekanth.reddy@avagotech.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>