mwifiex: remove unnecessary code in data rate configuration

1) Remove unnecessary wrapper functions.
2) Currently we don't have command to set Tx data rate, so
mwifiex_rate_ioctl_set_rate_value() function and related code
can be removed.
3) "ds_rate" filled by mwifiex_ret_tx_rate_cfg() is never used.

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/mwifiex/cfg80211.c b/drivers/net/wireless/mwifiex/cfg80211.c
index 7276a34..6914874 100644
--- a/drivers/net/wireless/mwifiex/cfg80211.c
+++ b/drivers/net/wireless/mwifiex/cfg80211.c
@@ -615,7 +615,7 @@
 mwifiex_dump_station_info(struct mwifiex_private *priv,
 			  struct station_info *sinfo)
 {
-	struct mwifiex_rate_cfg rate;
+	u32 rate;
 
 	sinfo->filled = STATION_INFO_RX_BYTES | STATION_INFO_TX_BYTES |
 			STATION_INFO_RX_PACKETS | STATION_INFO_TX_PACKETS |
@@ -661,7 +661,7 @@
 	sinfo->tx_packets = priv->stats.tx_packets;
 	sinfo->signal = priv->bcn_rssi_avg;
 	/* bit rate is in 500 kb/s units. Convert it to 100kb/s units */
-	sinfo->txrate.legacy = rate.rate * 5;
+	sinfo->txrate.legacy = rate * 5;
 
 	if (priv->bss_mode == NL80211_IFTYPE_STATION) {
 		sinfo->filled |= STATION_INFO_BSS_PARAM;