ath9k: Fix code mistake

The commit "ath9k: Process GTT interrupts" accidentally
had a line that was commented out.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 73a3655..5924f72d 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -524,7 +524,7 @@
 			 * successfully after a GTT interrupt, the GTT counter
 			 * gets reset to zero here.
 			 */
-			/* sc->gtt_cnt = 0; */
+			sc->gtt_cnt = 0;
 
 			ath_tx_edma_tasklet(sc);
 		} else {