P2P: Make sure wpa_s->global->p2p_group_formation gets cleared

This pointer is now used in number of places to check whether an
interface is in P2P Group Formation, so we better make sure it gets
cleared when group formation has been completed. This was done in
only some of the cases.

wpa_supplicant/p2p_supplicant.c

@@ -422,6 +422,7 @@ static void wpas_group_formation_completed(struct wpa_supplicant *wpa_s,
 	 */
 	if (wpa_s->global->p2p_group_formation)
 		wpa_s = wpa_s->global->p2p_group_formation;
+	wpa_s->global->p2p_group_formation = NULL;
 	wpa_s->p2p_in_provisioning = 0;
 
 	if (!success) {
@@ -782,6 +783,8 @@ static void p2p_go_configured(void *ctx, void *data)
 	ssid = wpa_s->current_ssid;
 	if (ssid && ssid->mode == WPAS_MODE_P2P_GO) {
 		wpa_printf(MSG_DEBUG, "P2P: Group setup without provisioning");
+		if (wpa_s->global->p2p_group_formation == wpa_s)
+			wpa_s->global->p2p_group_formation = NULL;
 		wpa_msg(wpa_s->parent, MSG_INFO, P2P_EVENT_GROUP_STARTED
 			"%s GO ssid=\"%s\" freq=%d passphrase=\"%s\" "
 			"go_dev_addr=" MACSTR "%s",