ath9k_hw: fix gentimer callback without overflow handler

If a gentimer has both the trigger and the overflow bits set, only
mask out the trigger bit if an overflow handler is present.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -3084,14 +3084,14 @@ void ath_gen_timer_isr(struct ath_hw *ah)
 	trigger_mask &= timer_table->timer_mask;
 	thresh_mask &= timer_table->timer_mask;
 
-	trigger_mask &= ~thresh_mask;
-
 	for_each_set_bit(index, &thresh_mask, ARRAY_SIZE(timer_table->timers)) {
 		timer = timer_table->timers[index];
 		if (!timer)
 		    continue;
 		if (!timer->overflow)
 		    continue;
+
+		trigger_mask &= ~BIT(index);
 		timer->overflow(timer->arg);
 	}