If one pci device is plugged successfully, there must be a zpci device
existing. This means that during hot-unplugging a pci device, its
corresponding zpci device must be found. Therefore we use an assert to
replace current code.
Signed-off-by: NYi Min Zhao <zyimin@linux.vnet.ibm.com>
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>