Some more locking needs to be added/modified for when
read-modify-writing sas_task.task_state_flags.

Note: since we can attempt to grab this lock in interrupt
      context we should use irq variant of spin_lock.
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>