[PATCH] acpi_smp_processor_id() warning fix

Suppress an "using smp_processor_id in preemptible code" warning.  The idle
thread isn't preemptible, so we can simply use _smp_processor_id().
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/acpi/processor_idle.c

@@ -162,7 +162,7 @@ static void acpi_processor_idle (void)
 	int			sleep_ticks = 0;
 	u32			t1, t2 = 0;
 
-	pr = processors[smp_processor_id()];
+	pr = processors[_smp_processor_id()];
 	if (!pr)
 		return;