mwifiex: make addba request command clean

uninitilized variable, such as .add_req_result might be magic stack
value. Initialize the structure to make it clean.
Signed-off-by: NXinming Hu <huxm@marvell.com>
Signed-off-by: NCathy Luo <cluo@marvell.com>
Signed-off-by: NKalle Valo <kvalo@codeaurora.org>

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

@@ -572,6 +572,8 @@ int mwifiex_send_addba(struct mwifiex_private *priv, int tid, u8 *peer_mac)
 
 	mwifiex_dbg(priv->adapter, CMD, "cmd: %s: tid %d\n", __func__, tid);
 
+	memset(&add_ba_req, 0, sizeof(add_ba_req));
+
 	if ((GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA) &&
 	    ISSUPP_TDLS_ENABLED(priv->adapter->fw_cap_info) &&
 	    priv->adapter->is_hw_11ac_capable &&