[IA64-SGI] fix bte_copy() calling get_nasid() while preemptible

bte_copy() calls calls get_nasid(), which will get flagged if
preemption if enabled.  raw_smp_processor_id() is used instead.
It is OK if we migrate off node.

Signed-off-by: Russ Anderson <(rja@sgi.com)>
Signed-off-by: Tony Luck <tony.luck@intel.com>