RDMA/rxe: Fix incorrect rxe_put in error path

In rxe_send() a ref is taken on the qp to keep it alive until the
kfree_skb() has a chance to call the skb destructor rxe_skb_tx_dtor()
which drops the reference. If the packet has an incorrect protocol the
error path just calls kfree_skb() which will call the destructor which
will drop the ref. Currently the driver also calls rxe_put() which is
incorrect. Additionally since the packets sent to rxe_send() are under the
control of the driver and it only ever produces IPV4 or IPV6 packets the
simplest fix is to remove all the code in this block.

Link: https://lore.kernel.org/r/20240329145513.35381-12-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Fixes: 9eb7f8e ("IB/rxe: Move refcounting earlier in rxe_send()")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Author: rpearsonhpe-design

drivers/infiniband/sw/rxe/rxe_net.c

@@ -366,18 +366,10 @@ static int rxe_send(struct sk_buff *skb, struct rxe_pkt_info *pkt)
 	rxe_get(pkt->qp);
 	atomic_inc(&pkt->qp->skb_out);
 
-	if (skb->protocol == htons(ETH_P_IP)) {
+	if (skb->protocol == htons(ETH_P_IP))
 		err = ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
-	} else if (skb->protocol == htons(ETH_P_IPV6)) {
+	else
 		err = ip6_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
-	} else {
-		rxe_dbg_qp(pkt->qp, "Unknown layer 3 protocol: %d\n",
-				skb->protocol);
-		atomic_dec(&pkt->qp->skb_out);
-		rxe_put(pkt->qp);
-		kfree_skb(skb);
-		return -EINVAL;
-	}
 
 	if (unlikely(net_xmit_eval(err))) {
 		rxe_dbg_qp(pkt->qp, "error sending packet: %d\n", err);