ath9k: Fix buffer overflow error

The commit "ath9k: stomp audio profiles on weak signal
strength" failed to take care of new stomp type while
programming concurrent tx priority. That leads to array
index out of bounds access.

drivers/net/wireless/ath/ath9k/btcoex.c:414
        ath9k_hw_btcoex_set_concur_txprio()
               error: buffer overflow 'stomp_txprio' 4 <= 4
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -257,8 +257,9 @@ static void ath_mci_set_concur_txprio(struct ath_softc *sc)
 {
 	struct ath_btcoex *btcoex = &sc->btcoex;
 	struct ath_mci_profile *mci = &btcoex->mci;
-	u8 stomp_txprio[] = { 0, 0, 0, 0 }; /* all, low, none, low_ftp */
+	u8 stomp_txprio[ATH_BTCOEX_STOMP_MAX];
 
+	memset(stomp_txprio, 0, sizeof(stomp_txprio));
 	if (mci->num_mgmt) {
 		stomp_txprio[ATH_BTCOEX_STOMP_ALL] = ATH_MCI_INQUIRY_PRIO;
 		if (!mci->num_pan && !mci->num_other_acl)