sched: Avoid expensive initial update_cfs_load(), on UP too

Fix the build on UP.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Turner <pjt@google.com>
LKML-Reference: <20110122044852.102126037@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/sched.c

@@ -7922,7 +7922,9 @@ static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq)
 #ifdef CONFIG_FAIR_GROUP_SCHED
 	cfs_rq->rq = rq;
 	/* allow initial update_cfs_load() to truncate */
+#ifdef CONFIG_SMP
 	cfs_rq->load_stamp = 1;
+#endif
 #endif
 	cfs_rq->min_vruntime = (u64)(-(1LL << 20));
 }