vfio-pci: Loosen sanity checks to allow future features

vfio-pci: Loosen sanity checks to allow future features

VFIO_PCI_NUM_REGIONS and VFIO_PCI_NUM_IRQS should never have been
used in this manner as it locks a specific kernel implementation.
Future features may introduce new regions or interrupt entries
(VGA may add legacy ranges, AER might add an IRQ for error
signalling).  Fix this before it gets us into trouble.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: qemu-stable@nongnu.org
(cherry picked from commit 8fc94e5a8046e349e07976f9bcaffbcd5833f3a2)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>