ath9k_hw: remove a useless WARN_ON

&ah->curchan->ani can never be NULL

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -419,9 +419,6 @@ void ath9k_hw_ani_monitor(struct ath_hw *ah, struct ath9k_channel *chan)
 		return;
 
 	aniState = &ah->curchan->ani;
-	if (WARN_ON(!aniState))
-		return;
-
 	if (!ath9k_hw_ani_read_counters(ah))
 		return;