qcacld-3.0: Add NULL check for rso_usr_cfg pointer

Add NULL check for rso_usr_cfg pointer to avoid NULL pointer
deference in function cm_update_advance_roam_scan_filter().

Change-Id: Ic7d0277705bafd551a8ee9f6cac7c479c71d187e
CRs-Fixed: 3626780

components/umac/mlme/connection_mgr/core/src/wlan_cm_host_util.c

@@ -80,6 +80,8 @@ QDF_STATUS cm_update_advance_roam_scan_filter(
 		return QDF_STATUS_E_FAILURE;
 
 	rso_usr_cfg = wlan_cm_get_rso_user_config(vdev);
+	if (!rso_usr_cfg)
+		return QDF_STATUS_E_INVAL;
 
 	mlme_debug("No of Allowed SSID List:%d",
 		   rso_usr_cfg->num_ssid_allowed_list);