[IA64] pci_acpi_scan_root cleanup

The code walks all the acpi _CRS methods to see how many windows
to allocate.  It then scans them all again to insert_resource()
for each *even if the first scan found that there were none*.

Move the second scan inside the "if (windows)" clause.

Signed-off-by: Tony Luck <tony.luck@intel.com>