qga-win: fsinfo: pci-info: allow partial info

qga-win: fsinfo: pci-info: allow partial info

The call to SetupDiGetDeviceRegistryProperty might fail because the
value doesn't exist in the registry, in this case we shouldn't exit from
the loop but instead continue to look for other available values in the
registry and set this value as unavailable (-1).

Signed-off-by: Sameeh Jubran <sjubran@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Tomáš Golembiovský <tgolembi@redhat.com>
*squash in fix for when get_pci_info() returns NULL pci_controller field
*fix handling for error_set() cases in get_pci_info(), not just NULL return
*force all -1 PCI addr fields if any single one of them isn't found
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>