PCI hotplug: remove redundant .owner initializations

The "owner" field in struct hotplug_slot_ops is initialized by PCI
hotplug core. So each hotplug controller driver doesn't need to
initialize it.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Reviewed-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>