rsi: remove set but not used variables 'header_size' and 'tx_params'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/net/wireless/rsi/rsi_91x_hal.c: In function 'rsi_send_data_pkt':
drivers/net/wireless/rsi/rsi_91x_hal.c:288:5: warning:
 variable 'header_size' set but not used [-Wunused-but-set-variable]

'tx_params' only used for 'header_size' dereferenced,so also
can be removed.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/rsi/rsi_91x_hal.c

@@ -282,10 +282,8 @@ int rsi_send_data_pkt(struct rsi_common *common, struct sk_buff *skb)
 	struct rsi_hw *adapter = common->priv;
 	struct ieee80211_vif *vif;
 	struct ieee80211_tx_info *info;
-	struct skb_info *tx_params;
 	struct ieee80211_bss_conf *bss;
 	int status = -EINVAL;
-	u8 header_size;
 
 	if (!skb)
 		return 0;
@@ -297,8 +295,6 @@ int rsi_send_data_pkt(struct rsi_common *common, struct sk_buff *skb)
 		goto err;
 	vif = info->control.vif;
 	bss = &vif->bss_conf;
-	tx_params = (struct skb_info *)info->driver_data;
-	header_size = tx_params->internal_hdr_size;
 
 	if (((vif->type == NL80211_IFTYPE_STATION) ||
 	     (vif->type == NL80211_IFTYPE_P2P_CLIENT)) &&