ath9k: set ATH_OP_INVALID before disabling hardware

Closes another small IRQ handler race
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/main.c

@@ -887,6 +887,9 @@ static void ath9k_stop(struct ieee80211_hw *hw)
 						    &sc->cur_chan->chandef);
 
 	ath9k_hw_reset(ah, ah->curchan, ah->caldata, false);
+
+	set_bit(ATH_OP_INVALID, &common->op_flags);
+
 	ath9k_hw_phy_disable(ah);
 
 	ath9k_hw_configpcipowersave(ah, true);
@@ -895,7 +898,6 @@ static void ath9k_stop(struct ieee80211_hw *hw)
 
 	ath9k_ps_restore(sc);
 
-	set_bit(ATH_OP_INVALID, &common->op_flags);
 	sc->ps_idle = prev_idle;
 
 	mutex_unlock(&sc->mutex);