liquidio: read sc->iq_no before release sc

[ Upstream commit c0f53771ba45745e5870daf880127925c93f232f ]

The function lio_vf_rep_packet_sent_callback releases the occupation of
sc via octeon_free_soft_command. sc should not be used after that.
Unfortunately, sc->iq_no is read. To fix this, the patch stores sc->iq_no
into a local variable before releasing sc and then uses the local variable
instead of sc->iq_no.
Signed-off-by: NPan Bian <bianpan2016@163.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSasha Levin <sashal@kernel.org>

drivers/net/ethernet/cavium/liquidio/lio_vf_rep.c

@@ -367,13 +367,15 @@ lio_vf_rep_packet_sent_callback(struct octeon_device *oct,
 	struct octeon_soft_command *sc = (struct octeon_soft_command *)buf;
 	struct sk_buff *skb = sc->ctxptr;
 	struct net_device *ndev = skb->dev;
+	u32 iq_no;
 
 	dma_unmap_single(&oct->pci_dev->dev, sc->dmadptr,
 			 sc->datasize, DMA_TO_DEVICE);
 	dev_kfree_skb_any(skb);
+	iq_no = sc->iq_no;
 	octeon_free_soft_command(oct, sc);
 
-	if (octnet_iq_is_full(oct, sc->iq_no))
+	if (octnet_iq_is_full(oct, iq_no))
 		return;
 
 	if (netif_queue_stopped(ndev))