[IA64] Remove NULL pointer check for argument never passed as NULL.

There is only palinfo_handle_smp as (indirect) user of palinfo_smp_call (by
way of smp_call_function_single) and surely palinfo_handle_smp never pass
NULL as parameter for info.

Signed-off-by: Simon Holm Thøgersen <odie@cs.aau.dk>
Signed-off-by: Tony Luck <tony.luck@intel.com>