In the libsas error path, SATA disks require extra handling in
libata to recover operation.  However, libsas expects to be able
to immediately recover all outstanding I/O once the error handler
escalation stops.  This patch fixes the condition where the libata
error handler is scheduled for operation but libsas has already
deleted the outstanding sas_tasks.
Signed-off-by: NJeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>