[IA64] IOSAPIC bogus error cleanup

On Altix (sn2) machines the "Error parsing MADT" message is
misleading because the lack of IOSAPIC entries is expected.

Since I am sure someone will ask, I have been told that
the chance of this changing anytime soon is close to nil.

Signed-off-by: George Beshers <gbeshers@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>