rsi: Delete unnecessary variable initialisation

In rsi_send_mgmt_pkt(), the following variables are assigned to
before they're used:

 * wh - Assigned on line 161, first used on line 180
 * bss - Assigned on line 160, first used on line 196
 * msg - Assigned on line 168, first used on line 175
 * extnd_size - Assigned on line 139, first used on line 142

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
[Rewrote commit message]
Signed-off-by: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/rsi/rsi_91x_pkt.c

@@ -123,15 +123,15 @@ int rsi_send_mgmt_pkt(struct rsi_common *common,
 		      struct sk_buff *skb)
 {
 	struct rsi_hw *adapter = common->priv;
-	struct ieee80211_hdr *wh = NULL;
+	struct ieee80211_hdr *wh;
 	struct ieee80211_tx_info *info;
-	struct ieee80211_bss_conf *bss = NULL;
+	struct ieee80211_bss_conf *bss;
 	struct ieee80211_hw *hw = adapter->hw;
 	struct ieee80211_conf *conf = &hw->conf;
 	struct skb_info *tx_params;
 	int status = -E2BIG;
-	__le16 *msg = NULL;
-	u8 extnd_size = 0;
+	__le16 *msg;
+	u8 extnd_size;
 	u8 vap_id = 0;
 
 	info = IEEE80211_SKB_CB(skb);