b43: fix ieee80211_rx() context

Due to the way it interacts with the networking
stack and other parts of mac80211, ieee80211_rx()
must be called with disabled softirqs.

[1] http://thread.gmane.org/gmane.linux.kernel.wireless.general/39440/focus=40266

Reported-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/b43/xmit.c

@@ -690,7 +690,10 @@ void b43_rx(struct b43_wldev *dev, struct sk_buff *skb, const void *_rxhdr)
 	}
 
 	memcpy(IEEE80211_SKB_RXCB(skb), &status, sizeof(status));
+
+	local_bh_disable();
 	ieee80211_rx(dev->wl->hw, skb);
+	local_bh_enable();
 
 #if B43_DEBUG
 	dev->rx_count++;