ath9k_htc: memory corruption calling set_bit()

In d8a2c51c ('ath9k_htc: Use atomic operations for op_flags') we
changed things like this:

-	if (priv->op_flags & OP_TSF_RESET) {
+	if (test_bit(OP_TSF_RESET, &priv->op_flags)) {

The problem is that test_bit() takes a bit number and not a mask.  It
means that when we do:

	set_bit(OP_TSF_RESET, &priv->op_flags);

Then it sets the (1 << 6) bit instead of the 6 bit so we are setting a
bit which is past the end of the unsigned long.

Fixes: d8a2c51c ('ath9k_htc: Use atomic operations for op_flags')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>