pseries: Fix array overrun bug in PCI code

spapr_populate_pci_devices() containd a loop with PCI_NUM_REGIONS (7)
iterations.  However this overruns the 'bars' global array, which only has
6 elements. In fact we only want to run this loop for things listed in the
bars array, so this patch corrects the loop bounds to reflect that.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NAndrzej Zaborowski <andrew.zaborowski@intel.com>

hw/spapr_pci.c

@@ -454,7 +454,7 @@ int spapr_populate_pci_devices(sPAPRPHBState *phb,
         reg[0].size = 0;
 
         n = 0;
-        for (i = 0; i < PCI_NUM_REGIONS; ++i) {
+        for (i = 0; i < ARRAY_SIZE(bars); ++i) {
             if (0 == dev->io_regions[i].size) {
                 continue;
             }