isci: Fix the terminated I/O to not call sas_task_abort().

This addresses a regression from the commit "isci: Redesign
device suspension, abort, cleanup." in which the sas_task end
condition for terminated I/Os was made to call back on
sas_task_abort()".
This commit will be rolled into the original.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>