ath9k: Fix uninitialized variable in ath9k_has_tx_pending()

drivers/net/wireless/ath/ath9k/main.c: In function ‘ath9k_has_tx_pending’:
drivers/net/wireless/ath/ath9k/main.c:1869: warning: ‘npend’ may be used uninitialized in this function

Introduced by commit 10e23181 ("ath9k:
optimize ath9k_flush").
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -1863,7 +1863,7 @@ static void ath9k_set_coverage_class(struct ieee80211_hw *hw, u8 coverage_class)
 
 static bool ath9k_has_tx_pending(struct ath_softc *sc)
 {
-	int i, npend;
+	int i, npend = 0;
 
 	for (i = 0; i < ATH9K_NUM_TX_QUEUES; i++) {
 		if (!ATH_TXQ_SETUP(sc, i))