qga: Fix guest-get-fsinfo PCI address collection in Windows

qga: Fix guest-get-fsinfo PCI address collection in Windows

The Windows QEMU guest agent erroneously tries to collect PCI information
directly from the physical drive. However, windows stores SCSI/IDE information
with the drive and PCI information with the underlying storage controller
This changes get_pci_info to use the physical drive's underlying storage
controller to get PCI information.

* Additionally Fixes incorrect size being passed to DeviceIoControl
  when getting volume extents. Can occasionally crash the guest agent

Signed-off-by: Matt Hines <mhines@scalecomputing.com>
*fix up some checkpatch warnings
*fix domain reporting and add some sanity checks for debug
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>