ath9k_hw: fix a sign error in the IQ calibration code

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Cc: stable@kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/ar9002_calib.c b/drivers/net/wireless/ath/ath9k/ar9002_calib.c
index 5fdbb53..dabafb8 100644
--- a/drivers/net/wireless/ath/ath9k/ar9002_calib.c
+++ b/drivers/net/wireless/ath/ath9k/ar9002_calib.c
@@ -239,7 +239,7 @@
 			if (qCoff > 15)
 				qCoff = 15;
 			else if (qCoff <= -16)
-				qCoff = 16;
+				qCoff = -16;
 
 			ath_print(common, ATH_DBG_CALIBRATE,
 				  "Chn %d : iCoff = 0x%x  qCoff = 0x%x\n",