mt76: fix corrupted software generated tx CCMP PN

[ Upstream commit 906d2d3f874a54183df5a609fda180adf0462428 ]

Since ccmp_pn is u8 *, the second half needs to start at array index 4
instead of 0. Fixes a connection stall after a certain amount of traffic

Fixes: 23405236460b9 ("mt76: fix transmission of encrypted management frames")
Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/net/wireless/mediatek/mt76/mt76x2_mac_common.c

@@ -402,7 +402,7 @@ void mt76x2_mac_write_txwi(struct mt76x2_dev *dev, struct mt76x2_txwi *txwi,
 		ccmp_pn[6] = pn >> 32;
 		ccmp_pn[7] = pn >> 40;
 		txwi->iv = *((__le32 *)&ccmp_pn[0]);
-		txwi->eiv = *((__le32 *)&ccmp_pn[1]);
+		txwi->eiv = *((__le32 *)&ccmp_pn[4]);
 	}
 
 	spin_lock_bh(&dev->mt76.lock);