Fix sched_scan filter_ssids setting for no filters case

The filter_ssids pointer needs to be set to NULL if no SSID filters
are set to avoid filtering out all scan results.

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

wpa_supplicant/scan.c

@@ -787,6 +787,11 @@ int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 		ssid = ssid->next;
 	}
 
+	if (params.num_filter_ssids == 0) {
+		os_free(params.filter_ssids);
+		params.filter_ssids = NULL;
+	}
+
 	if (wpa_s->wps)
 		wps_ie = wpa_supplicant_extra_ies(wpa_s, &params);