[SCSI] ses: fix problems caused by empty SES provided name

We use the name provided by SES to name objects.  An empty name is
legal in SES but causes problems in our generic device hierarchy.  Fix
this by falling back to a number if the name is either NULL or empty.

Also fix a secondary bug spotted in that dev_set_name(dev, name) uses
a string format and so would go wrong if name contained a '%'.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>