mwifiex: declare sta_ptr in smaller scope

sta_ptr is used only in an 'if' branch in this function.
Move it to the smaller scope where it is used.
Reported-by: Paul Stewart <pstew@chromium.org>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: Avinash Patil <patila@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/mwifiex/11n.c

@@ -541,7 +541,6 @@ void mwifiex_create_ba_tbl(struct mwifiex_private *priv, u8 *ra, int tid,
 int mwifiex_send_addba(struct mwifiex_private *priv, int tid, u8 *peer_mac)
 {
 	struct host_cmd_ds_11n_addba_req add_ba_req;
-	struct mwifiex_sta_node *sta_ptr;
 	u32 tx_win_size = priv->add_ba_param.tx_win_size;
 	static u8 dialog_tok;
 	int ret;
@@ -553,6 +552,8 @@ int mwifiex_send_addba(struct mwifiex_private *priv, int tid, u8 *peer_mac)
 	    ISSUPP_TDLS_ENABLED(priv->adapter->fw_cap_info) &&
 	    priv->adapter->is_hw_11ac_capable &&
 	    memcmp(priv->cfg_bssid, peer_mac, ETH_ALEN)) {
+		struct mwifiex_sta_node *sta_ptr;
+
 		sta_ptr = mwifiex_get_sta_entry(priv, peer_mac);
 		if (!sta_ptr) {
 			dev_warn(priv->adapter->dev,