ath9k: fix RSSI dummy marker value

RSSI is being stored internally as s8 in several places. The indication
of an unset RSSI value, ATH_RSSI_DUMMY_MARKER, was supposed to have been
set to 127, but ended up being set to 0x127 because of a code cleanup
mistake. This could lead to invalid signal strength values in a few
places.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Cc: stable@vger.kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/common.h

@@ -27,7 +27,7 @@
 #define WME_MAX_BA              WME_BA_BMP_SIZE
 #define ATH_TID_MAX_BUFS        (2 * WME_MAX_BA)
 
-#define ATH_RSSI_DUMMY_MARKER   0x127
+#define ATH_RSSI_DUMMY_MARKER   127
 #define ATH_RSSI_LPF_LEN 		10
 #define RSSI_LPF_THRESHOLD		-20
 #define ATH_RSSI_EP_MULTIPLIER     (1<<7)