[IA64-SGI] fix for-loop in sn_hwperf_geoid_to_cnode()

Fix a for-loop in sn_hwperf_geoid_to_cnode().  It needs to loop over
num_cnodes to ensure it can still process TIO nodes in addition to
compute nodes on systems with many nodes.  Interim fix until better
support for many (>265) nodes is complete.

Signed-off-by: Dean Roe <roe@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>