pciinit: fix off-by-one

IO port ends at 64K - 1. not 64K.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
diff --git a/src/pciinit.c b/src/pciinit.c
index 795672b..ee2e72d 100644
--- a/src/pciinit.c
+++ b/src/pciinit.c
@@ -402,7 +402,7 @@
 
     dprintf(3, "pci setup\n");
 
-    pci_region_init(&pci_bios_io_region, 0xc000, 64 * 1024);
+    pci_region_init(&pci_bios_io_region, 0xc000, 64 * 1024 - 1);
     pci_region_init(&pci_bios_mem_region,
                     BUILD_PCIMEM_START, BUILD_PCIMEM_END - 1);
     pci_region_init(&pci_bios_prefmem_region,