ia64/PCI: Fix incorrect PCI resource end address

commit f976721e826e ("ia64/PCI: Use ioremap() instead of open-coded
equivalent") introduced the following compiler warning,

  arch/ia64/sn/kernel/io_init.c: In function 'sn_io_slot_fixup':
  arch/ia64/sn/kernel/io_init.c:189:19: warning: 'addr' may be used uninitialized in this function [-Wmaybe-uninitialized]
     res->end = addr + size;
                   ^

'addr' is indeed uninitialised and the correct value to use is
res->start.

Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Bjorn Helgaas <helgaas@kernel.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/sn/kernel/io_init.c

@@ -151,7 +151,7 @@ sn_io_slot_fixup(struct pci_dev *dev)
 {
 	int idx;
 	struct resource *res;
-	unsigned long addr, size;
+	unsigned long size;
 	struct pcidev_info *pcidev_info;
 	struct sn_irq_info *sn_irq_info;
 	int status;
@@ -186,7 +186,7 @@ sn_io_slot_fixup(struct pci_dev *dev)
 			continue;
 
 		res->start = pcidev_info->pdi_pio_mapped_addr[idx];
-		res->end = addr + size;
+		res->end = res->start + size;
 
 		/*
 		 * if it's already in the device structure, remove it before