ath5k: Fix lockup due to un-init spinlock.

This was introduced in 2.6.39-rc1 it seems.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Tested-by: Sedat Dilek <sedat.dilek@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath5k/base.c

@@ -2394,7 +2394,7 @@ ath5k_init_softc(struct ath5k_softc *sc, const struct ath_bus_ops *bus_ops)
 	spin_lock_init(&sc->rxbuflock);
 	spin_lock_init(&sc->txbuflock);
 	spin_lock_init(&sc->block);
-
+	spin_lock_init(&sc->irqlock);
 
 	/* Setup interrupt handler */
 	ret = request_irq(sc->irq, ath5k_intr, IRQF_SHARED, "ath", sc);