Fix memory corruption reported by Julian Seward

  (still more bugs to fix in PreP emulation).


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3390 c046a42c-6fe2-441c-8c8c-71466251a162

hw/prep_pci.c

@@ -135,7 +135,7 @@ PCIBus *pci_prep_init(qemu_irq *pic)
     int PPC_io_memory;
 
     s = qemu_mallocz(sizeof(PREPPCIState));
-    s->bus = pci_register_bus(prep_set_irq, prep_map_irq, pic, 0, 2);
+    s->bus = pci_register_bus(prep_set_irq, prep_map_irq, pic, 0, 4);
 
     register_ioport_write(0xcf8, 4, 4, pci_prep_addr_writel, s);
     register_ioport_read(0xcf8, 4, 4, pci_prep_addr_readl, s);