This field was added in commit 44510d6fa0 ("s390/pci: Handling
multifunctions") but is an unused remnant of an earlier version where
the devices on the virtual bus were connected in a linked list instead
of a fixed 256 entry array of pointers.
It is also not used for the list of busses as that is threaded through
struct zpci_bus not through struct zpci_dev.
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>