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

bte_copy() calls calls smp_processor_id(), which will get flagged if
preemption if enabled.  raw_smp_processor_id() is used instead 
because we are just using it to pick a BTE interface and are not 
tied to a specific cpu.

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