rsi: remove set but not used variables 'info, vif'

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

drivers/net/wireless/rsi/rsi_91x_main.c: In function 'rsi_prepare_skb':
drivers/net/wireless/rsi/rsi_91x_main.c:127:24: warning:
 variable 'vif' set but not used [-Wunused-but-set-variable]

drivers/net/wireless/rsi/rsi_91x_main.c:124:28: warning:
 variable 'info' set but not used [-Wunused-but-set-variable]

They're not used any more since 160ee2a1 ("rsi: fill rx_params only once.")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/rsi/rsi_91x_main.c

@@ -121,11 +121,8 @@ static struct sk_buff *rsi_prepare_skb(struct rsi_common *common,
 				       u32 pkt_len,
 				       u8 extended_desc)
 {
-	struct ieee80211_tx_info *info;
 	struct sk_buff *skb = NULL;
 	u8 payload_offset;
-	struct ieee80211_vif *vif;
-	struct ieee80211_hdr *wh;
 
 	if (WARN(!pkt_len, "%s: Dummy pkt received", __func__))
 		return NULL;
@@ -144,10 +141,7 @@ static struct sk_buff *rsi_prepare_skb(struct rsi_common *common,
 	payload_offset = (extended_desc + FRAME_DESC_SZ);
 	skb_put(skb, pkt_len);
 	memcpy((skb->data), (buffer + payload_offset), skb->len);
-	wh = (struct ieee80211_hdr *)skb->data;
-	vif = rsi_get_vif(common->priv, wh->addr1);
 
-	info = IEEE80211_SKB_CB(skb);
 	return skb;
 }