Simple Observer: Cancel the discovery during discovery process received ERROR and need to reset the board

Update: reproduced in 3.20.00.18

Note:The bug doesn't reproduced on version:2.20.00.43

Setup:

DUT Chameleon BLE3 version 2.30.00.08

Tera Term TV

Description:

1. Load simple_observer_cc2640r2lp_app_FlashROM_StackLibrary_ccs.hex to the device

2. Connect to device with Tera Term

3. Start discovery by push on BTN2

4. Cancel the discovery by push on BTN2 again

Problem:

Received ERROR and need to reset the board