There is no standard Smarts IP feature to disable a device from showing in the pending list if it fails during rediscovery. However, you can achieve this functionality using a customized script. To do this, create a script with the following command:
./dmctl -s INCHARGE-AM-PM invoke AD_Pending::AD-Pending removePending <Device IP>
This command will remove the device from pending list if the device is already discovered and now reports unresponsive.