[IA64-SGI] sn_console.c minor cleanup

Fix printk level and remove unnecessary CONFIG_SMP|CONFIG_PREEMPT tests
as this is taken care through the spinlock macros anyway.

Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Pat Gefre <pfg@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>