[IA64-SGI] Hotplug driver related fix in the SN ia64 code.

Remove an erroneous kfree, and unlink the pcidev_info struct from the
pcidev_info list prior to free'ing the pcidev_info struct.

Signed-off-by: Prarit Bhargava <prarit@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>