[WATCHDOG] wdt_pci: fix printk and variable type

Fix printk format warning:
drivers/watchdog/wdt_pci.c:652: warning: format '%04x' expects type 'unsigned int', but argument 2 has type 'resource_size_t'

and then use resource_size_t for the "io" variable as well
so that it won't be truncated.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>