mwifiex: usb: unlock on error in mwifiex_usb_tx_aggr_tmo()

We need to unlock if mwifiex_usb_prepare_tx_aggr_skb() fails.

Fixes: a2ca85ad721d ("mwifiex: usb: add timer to flush aggregation packets")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/marvell/mwifiex/usb.c

@@ -1112,7 +1112,7 @@ static void mwifiex_usb_tx_aggr_tmo(unsigned long context)
 	if (err) {
 		mwifiex_dbg(adapter, ERROR,
 			    "prepare tx aggr skb failed, err=%d\n", err);
-		return;
+		goto unlock;
 	}
 
 	if (atomic_read(&port->tx_data_urb_pending) >=
@@ -1133,6 +1133,7 @@ static void mwifiex_usb_tx_aggr_tmo(unsigned long context)
 done:
 	if (err == -1)
 		mwifiex_write_data_complete(adapter, skb_send, 0, -1);
+unlock:
 	spin_unlock_irqrestore(&port->tx_aggr_lock, flags);
 }