scsi: dpt_i2o: use after free in adpt_release()

The scsi_host_put() function frees "pHba" and then we dereference it on
the next line when we do "scsi_host_put(pHba->host);".

[mkp: included fix from hch]

Fixes: 38e09e3b ("scsi: dpt_i2o: stop using scsi_unregister")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>