Many times in libsas, and in LLDDs which use libsas, the check for an
expander device is re-implemented or open coded.

Use dev_is_expander() instead. We rename this from
sas_dev_type_is_expander() to not spill so many lines in referencing.
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Reviewed-by: NJack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>