PCI: SGI Hotplug: stop managing bss_hotplug_slot->name

We no longer need to manage our version of hotplug_slot->name
since the PCI and hotplug core manage it on our behalf.

Update the sn_hp_slot_private_alloc() interface to fill in
the correct name for us, as that function already has all
the parameters needed to determine the name.

Cc: kristen.c.accardi@intel.com
Cc: jpk@sgi.com
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>