scsi: isci: fix typo in function names

There are a couple of typos in function names and spelling of request
where the letters u and e are swapped:

scu_ssp_reqeust_construct_task_context
scu_sata_reqeust_construct_task_context

Fix the spelling of request.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>