net: rds: use this_cpu_* per-cpu helper

Signed-off-by: Shan Wei <davidshan@tencent.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/rds/ib.h b/net/rds/ib.h
index 8d2b3d5..7280ab8 100644
--- a/net/rds/ib.h
+++ b/net/rds/ib.h
@@ -50,7 +50,7 @@
 };
 
 struct rds_ib_refill_cache {
-	struct rds_ib_cache_head *percpu;
+	struct rds_ib_cache_head __percpu *percpu;
 	struct list_head	 *xfer;
 	struct list_head	 *ready;
 };