TDLS: Fix add/set STA operation

Commit a9a1d0f08a added vht_capabilities
to struct hostapd_sta_add_params but forgot to update
wpa_supplicant_tdls_peer_addset() to initialize the variable to NULL.
This could result in uninitialized pointer being used in
driver_nl80211.c when adding a TDLS peer entry. Fix this by clearing the
hostapd_sta_add_params with memset.

Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>

wpa_supplicant/wpas_glue.c

@@ -557,6 +557,8 @@ static int wpa_supplicant_tdls_peer_addset(
 	struct wpa_supplicant *wpa_s = ctx;
 	struct hostapd_sta_add_params params;
 
+	os_memset(&params, 0, sizeof(params));
+
 	params.addr = peer;
 	params.aid = 1;
 	params.capability = capability;