scsi_transport_sas: Remove check for SAS expander when querying bay/enclosure IDs.

Dell Server backplanes can report bay/enclosure IDs without an
expander present.  This patch allows the bay/enclosure IDs to be
propagaged to sysfs.we

Signed-off-by: Jordan Hargrave <jordan_hargrave@dell.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>