orinoco: Move context allocation after processing the skb

ezusb_xmit() allocates a context which is leaked if
orinoco_process_xmit_skb() returns an error.

Move ezusb_alloc_ctx() after the invocation of
orinoco_process_xmit_skb() because the context is not needed so early.
ezusb_access_ltv() will cleanup the context in case of an error.

Fixes: bac6faf ("orinoco: refactor xmit path")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20201113212252.2243570-2-bigeasy@linutronix.de

drivers/net/wireless/intersil/orinoco/orinoco_usb.c

@@ -1221,20 +1221,20 @@ static netdev_tx_t ezusb_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (skb->len < ETH_HLEN)
 		goto drop;
 
-	ctx = ezusb_alloc_ctx(upriv, EZUSB_RID_TX, 0);
-	if (!ctx)
-		goto busy;
-
-	memset(ctx->buf, 0, BULK_BUF_SIZE);
-	buf = ctx->buf->data;
-
 	tx_control = 0;
 
 	err = orinoco_process_xmit_skb(skb, dev, priv, &tx_control,
 				       &mic[0]);
 	if (err)
 		goto drop;
 
+	ctx = ezusb_alloc_ctx(upriv, EZUSB_RID_TX, 0);
+	if (!ctx)
+		goto drop;
+
+	memset(ctx->buf, 0, BULK_BUF_SIZE);
+	buf = ctx->buf->data;
+
 	{
 		__le16 *tx_cntl = (__le16 *)buf;
 		*tx_cntl = cpu_to_le16(tx_control);