This patch fixes a null-pointer dereference when hot-plug operations
are performed on a machine that has virtual-io devices in it.
Virtual i/o devices to not have pci bridges associated with them.
It also corrects an ordering problem during hotplug remove.

This patch was previously reviewed/tested by Linda Xie, the current
rpaphp maintainer.
Signed-off-by: Linas Vepstas <linas@linas.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>