RDMA/cxgb4: Remove unneeded assignment

We don't need to assign rpl here, we do that later on.
Signed-off-by: Dan Carpenter <error27@gmail.com>

[ Indeed this assignment makes no sense, since skb is set to NULL a
  couple of lines before.  - Roland ]
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/cxgb4/cm.c

@@ -2244,7 +2244,7 @@ static void process_work(struct work_struct *work)
 {
 	struct sk_buff *skb = NULL;
 	struct c4iw_dev *dev;
-	struct cpl_act_establish *rpl = cplhdr(skb);
+	struct cpl_act_establish *rpl;
 	unsigned int opcode;
 	int ret;