b43legacy: rewrite and fix rfkill initialization

The rfkill subsystem doesn't like code like that
rfkill_allocate();
rfkill_register();
rfkill_unregister();
rfkill_register(); /* <- This will crash */

This sequence happens with
modprobe b43
ifconfig wlanX up
ifconfig wlanX down
ifconfig wlanX up

Fix this by always re-allocating the rfkill stuff before register.

The patch to b43 by Michael Buesch <mb@bu3sch.de> has been ported to
b43legacy.

Signed-off-by: Stefano Brivio <stefano.brivio@polimi.it>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/b43legacy/rfkill.h b/drivers/net/wireless/b43legacy/rfkill.h
index b68215e..11150a8 100644
--- a/drivers/net/wireless/b43legacy/rfkill.h
+++ b/drivers/net/wireless/b43legacy/rfkill.h
@@ -16,14 +16,14 @@
 	struct rfkill *rfkill;
 	/* The poll device for the RFKILL input button */
 	struct input_polled_dev *poll_dev;
+	/* Did initialization succeed? Used for freeing. */
+	bool registered;
 	/* The unique name of this rfkill switch */
-	char name[32];
+	char name[sizeof("b43legacy-phy4294967295")];
 };
 
-/* All the init functions return void, because we are not interested
+/* The init function returns void, because we are not interested
  * in failing the b43 init process when rfkill init failed. */
-void b43legacy_rfkill_alloc(struct b43legacy_wldev *dev);
-void b43legacy_rfkill_free(struct b43legacy_wldev *dev);
 void b43legacy_rfkill_init(struct b43legacy_wldev *dev);
 void b43legacy_rfkill_exit(struct b43legacy_wldev *dev);