mac80211: Print unknown packet type in tasklet_handler

In stress testing p54usb, the WARN_ON() in ieee80211_tasklet_handler() was
triggered; however, there is no logging of the received value for packet
type. Adding that feature will improve the warning.
Signed-off-by: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

net/mac80211/main.c

@@ -341,7 +341,8 @@ static void ieee80211_tasklet_handler(unsigned long data)
 			dev_kfree_skb(skb);
 			break ;
 		default:
-			WARN_ON(1);
+			WARN(1, "mac80211: Packet is of unknown type %d\n",
+			     skb->pkt_type);
 			dev_kfree_skb(skb);
 			break;
 		}