scsi: libsas: Refactor sas_queue_deferred_work()

In the second part of function __sas_drain_work(), deferred work is queued.
This functionality is required other places so factor it out into the
function sas_queue_deferred_work().

Link: https://lore.kernel.org/r/1639999298-244569-12-git-send-email-chenxiang66@hisilicon.com


Reviewed-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>