This function is documented to return the number of unregistered
callbacks or negative numbers on error, but pci_vfio checks for
ret != 0 to detect failures. Not anymore.
Fixes: c115fd000c ("vfio: handle hotplug request notifier")
Signed-off-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
d59ba0296e