rt2x00: Fix HT40+/HT40- setting in rt2800.

Inspection of the Ralink vendor driver shows that the TX_BAND_CFG register
and BBP register 3 are about HT40- indication, not about HT40+ indication.
Inverse the meaning of these fields in the code.
Signed-off-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2800.h

@@ -845,7 +845,7 @@
  * TX_BAND_CFG: 0x1 use upper 20MHz, 0x0 use lower 20MHz
  */
 #define TX_BAND_CFG			0x132c
-#define TX_BAND_CFG_HT40_PLUS		FIELD32(0x00000001)
+#define TX_BAND_CFG_HT40_MINUS		FIELD32(0x00000001)
 #define TX_BAND_CFG_A			FIELD32(0x00000002)
 #define TX_BAND_CFG_BG			FIELD32(0x00000004)
 
@@ -1519,7 +1519,7 @@ struct mac_iveiv_entry {
  * BBP 3: RX Antenna
  */
 #define BBP3_RX_ANTENNA			FIELD8(0x18)
-#define BBP3_HT40_PLUS			FIELD8(0x20)
+#define BBP3_HT40_MINUS			FIELD8(0x20)
 
 /*
  * BBP 4: Bandwidth

drivers/net/wireless/rt2x00/rt2800lib.c

@@ -867,7 +867,7 @@ static void rt2800_config_channel(struct rt2x00_dev *rt2x00dev,
 	}
 
 	rt2800_register_read(rt2x00dev, TX_BAND_CFG, &reg);
-	rt2x00_set_field32(&reg, TX_BAND_CFG_HT40_PLUS, conf_is_ht40_plus(conf));
+	rt2x00_set_field32(&reg, TX_BAND_CFG_HT40_MINUS, conf_is_ht40_minus(conf));
 	rt2x00_set_field32(&reg, TX_BAND_CFG_A, rf->channel > 14);
 	rt2x00_set_field32(&reg, TX_BAND_CFG_BG, rf->channel <= 14);
 	rt2800_register_write(rt2x00dev, TX_BAND_CFG, reg);
@@ -900,7 +900,7 @@ static void rt2800_config_channel(struct rt2x00_dev *rt2x00dev,
 	rt2800_bbp_write(rt2x00dev, 4, bbp);
 
 	rt2800_bbp_read(rt2x00dev, 3, &bbp);
-	rt2x00_set_field8(&bbp, BBP3_HT40_PLUS, conf_is_ht40_plus(conf));
+	rt2x00_set_field8(&bbp, BBP3_HT40_MINUS, conf_is_ht40_minus(conf));
 	rt2800_bbp_write(rt2x00dev, 3, bbp);
 
 	if (rt2x00_rt_rev(rt2x00dev, RT2860, REV_RT2860C)) {