scsi: libsas: Introduce SAS address comparison helpers

scsi: libsas: Introduce SAS address comparison helpers

SAS address comparison is widely used in libsas. However they are all
opencoded and to avoid the line spill over 80 columns, are mostly split
into multi-lines. Introduce some helpers to prepare for some refactoring.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Link: https://lore.kernel.org/r/20220928070130.3657183-2-yanaijie@huawei.com
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>