SLAB: Fix unlikely() annotation in __cache_alloc_node()

Branch profiling on my nehalem machine showed 99% incorrect branch hints:

   28459  7678524  99 __cache_alloc_node             slab.c               3551

Discussion on lkml [1] led to the solution to remove this hint.

[1] http://patchwork.kernel.org/patch/63517/Signed-off-by: Tim Blechmann <tim@klingt.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

mm/slab.c

@@ -3320,7 +3320,7 @@ __cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid,
 	cache_alloc_debugcheck_before(cachep, flags);
 	local_irq_save(save_flags);
 
-	if (unlikely(nodeid == -1))
+	if (nodeid == -1)
 		nodeid = numa_node_id();
 
 	if (unlikely(!cachep->nodelists[nodeid])) {