Ath5k: mask out unneeded interrupts

Mask out previously demanded interrupt flags because we set
new ones. Don't allow mixing them after switch from sta to
ibss and vice versa.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Nick Kossifidis <mickflemm@gmail.com>
Cc: Luis R. Rodriguez <mcgrof@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath5k/base.c

@@ -2170,6 +2170,7 @@ ath5k_beacon_config(struct ath5k_softc *sc)
 
 	ath5k_hw_set_intr(ah, 0);
 	sc->bmisscount = 0;
+	sc->imask &= ~(AR5K_INT_BMISS | AR5K_INT_SWBA);
 
 	if (sc->opmode == IEEE80211_IF_TYPE_STA) {
 		sc->imask |= AR5K_INT_BMISS;