xl: fix PCI resource parsing

xl: fix PCI resource parsing

The parsing of PCI resources has two problems:

   1. it assumes devices are 32-bits, whereas the fields in the
      "resources" file can have full 64-bit values
   2. it only parses the first resource because the format string is
      missing a \n

Fix both of these up, which allows my Intel 82574L to work with MSI-X.

However, this should probably be using a PCI access library rather
than rummaging around in /sys/bus/pci...

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>