b43: fix invalid memory access in b43_ssb_remove()

wldev is freed in b43_one_core_detach() and should not be accessed after
that call.  Keep wldev->dev in a local variable.
Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/b43/main.c

@@ -5350,6 +5350,7 @@ static void b43_ssb_remove(struct ssb_device *sdev)
 {
 	struct b43_wl *wl = ssb_get_devtypedata(sdev);
 	struct b43_wldev *wldev = ssb_get_drvdata(sdev);
+	struct b43_bus_dev *dev = wldev->dev;
 
 	/* We must cancel any work here before unregistering from ieee80211,
 	 * as the ieee80211 unreg will destroy the workqueue. */
@@ -5365,14 +5366,14 @@ static void b43_ssb_remove(struct ssb_device *sdev)
 		ieee80211_unregister_hw(wl->hw);
 	}
 
-	b43_one_core_detach(wldev->dev);
+	b43_one_core_detach(dev);
 
 	if (list_empty(&wl->devlist)) {
 		b43_leds_unregister(wl);
 		/* Last core on the chip unregistered.
 		 * We can destroy common struct b43_wl.
 		 */
-		b43_wireless_exit(wldev->dev, wl);
+		b43_wireless_exit(dev, wl);
 	}
 }