ath9k_htc: Add support for TX completion

Now that the infrastructure is in place, process WMI
TX status events and complete packets.

Signed-off-by: Sujith Manoharan <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/wmi.h b/drivers/net/wireless/ath/ath9k/wmi.h
index 8c877dc..44b1738 100644
--- a/drivers/net/wireless/ath/ath9k/wmi.h
+++ b/drivers/net/wireless/ath/ath9k/wmi.h
@@ -45,9 +45,9 @@
 /*
  * 64 - HTC header - WMI header - 1 / txstatus
  * And some other hdr. space is also accounted for.
- * 13 seems to be the magic number.
+ * 12 seems to be the magic number.
  */
-#define HTC_MAX_TX_STATUS 13
+#define HTC_MAX_TX_STATUS 12
 
 #define ATH9K_HTC_TXSTAT_ACK        BIT(0)
 #define ATH9K_HTC_TXSTAT_FILT       BIT(1)