re: carl9170: improve unicast PS buffering

[Dan Carpenter <dan.carpenter@oracle.com>]

Hello Christian Lamparter,

Sorry this is so old.  I was going through some old Smatch warnings.

This is a semi-automatic email about new static checker warnings.

The patch caf1eae20668: "carl9170: improve unicast PS buffering" from 
Apr 24, 2011, leads to the following Smatch complaint:

drivers/net/wireless/ath/carl9170/tx.c:1488 carl9170_op_tx()
	 error: we previously assumed 'sta' could be null (see line 1482)

drivers/net/wireless/ath/carl9170/tx.c
  1481	
  1482		if (sta) {
                   ^^^^^
New check.

  1483			struct carl9170_sta_info *stai = (void *) sta->drv_priv;
  1484			atomic_inc(&stai->pending_frames);
  1485		}
  1486	
  1487		if (info->flags & IEEE80211_TX_CTL_AMPDU) {
  1488			run = carl9170_tx_ampdu_queue(ar, sta, skb);
                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Old dereference of "sta" inside the call to carl9170_tx_ampdu_queue().

  1489			if (run)
  1490				carl9170_tx_ampdu(ar);

Probably we can remove the check?

regards,
dan carpenter