scsi: mpt3sas: Incorrect command status was set/marked as not used.

In _scsih_scan_finished driver should mark port_enable_cmd.status as
'command not used', instead base_cmds.status was marked as 'command not
used'. Update code to mark port_enable_cmd.status as 'command not used'.

Signed-off-by: Chaitra P B <chaitra.basappa@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>