IB/rxe: avoid double kfree skb

In rxe_send, when network_type is not RDMA_NETWORK_IPV4 or
RDMA_NETWORK_IPV6, skb is freed and -EINVAL is returned.
Then rxe_xmit_packet will return -EINVAL, too. In rxe_requester,
this skb is double freed.
In rxe_requester, kfree_skb is needed only after fill_packet fails.
So kfree_skb is moved from label err to test fill_packet.

Fixes: 5793b46521 ("IB/rxe: remove unnecessary skb_clone in xmit")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Zhu Yanjun <yanjun.zhu@oracle.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/sw/rxe/rxe_req.c

@@ -709,6 +709,7 @@ next_wqe:
 
 	if (fill_packet(qp, wqe, &pkt, skb, payload)) {
 		pr_debug("qp#%d Error during fill packet\n", qp_num(qp));
+		kfree_skb(skb);
 		goto err;
 	}
 
@@ -740,7 +741,6 @@ next_wqe:
 	goto next_wqe;
 
 err:
-	kfree_skb(skb);
 	wqe->status = IB_WC_LOC_PROT_ERR;
 	wqe->state = wqe_state_error;
 	__rxe_do_task(&qp->comp.task);