libertas: fix sleep confirmation

This fixes an issus that made "iwconfig eth1 power on" non-working.
When we get a "PS sleep" event, we have to confirm this to the firmware.
The confirm happens with a command, but this command is special: the
firmware won't send us a response. if_cs_host_to_card() is setting
priv->dnld_sent anyway, so this variable stayed at DNLD_DATA_SENT and
was never cleared back.

Now I put the special knowledge that the CMD_802_11_PS_MODE with
CMD_SUBCMD_SLEEP_CONFIRMED doesn't need to need a response by directly
clearing the dnld_sent state in lbs_send_confirmsleep().

Signed-off-by: Holger Schurig <hs4233@mail.mn-solutions.de>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/libertas/main.c b/drivers/net/wireless/libertas/main.c
index e1f0660..acfc4bf 100644
--- a/drivers/net/wireless/libertas/main.c
+++ b/drivers/net/wireless/libertas/main.c
@@ -732,8 +732,8 @@
 		lbs_deb_thread("4: currenttxskb %p, dnld_sent %d\n",
 		       priv->currenttxskb, priv->dnld_sent);
 
-		spin_lock_irq(&priv->driver_lock);
 		/* Process any pending command response */
+		spin_lock_irq(&priv->driver_lock);
 		resp_idx = priv->resp_idx;
 		if (priv->resp_len[resp_idx]) {
 			spin_unlock_irq(&priv->driver_lock);