app/wifi: fix wi-fi on off test program
app/wifi: fix wi-fi on off test program

Fix wi-fi on off test program.
1) Remove code handling exceptional cases like no callback from wi-fi devices.
2) Remove unused code.

jeongchanKim/TizenRT,sunghan-chang/TizenRT,junmin-kim/TizenRT,jeongchanKim/TizenRT,Samsung/TizenRT,sunghan-chang/TizenRT,jsdosa/TizenRT,pillip8282/TizenRT,jeongarmy/TizenRT,jeongchanKim/TizenRT,an4967/TizenRT,jeongarmy/TizenRT,an4967/TizenRT,jsdosa/TizenRT,pillip8282/TizenRT,jsdosa/TizenRT,an4967/TizenRT,sunghan-chang/TizenRT,jeongchanKim/TizenRT,an4967/TizenRT,jeongarmy/TizenRT,an4967/TizenRT,sunghan-chang/TizenRT,jeongarmy/TizenRT,Samsung/TizenRT,junmin-kim/TizenRT,jeongchanKim/TizenRT,sunghan-chang/TizenRT,junmin-kim/TizenRT,junmin-kim/TizenRT,jeongchanKim/TizenRT,jeongchanKim/TizenRT,pillip8282/TizenRT,an4967/TizenRT,jeongarmy/TizenRT,sunghan-chang/TizenRT,jsdosa/TizenRT,sunghan-chang/TizenRT,pillip8282/TizenRT,an4967/TizenRT,jeongarmy/TizenRT,jsdosa/TizenRT,jsdosa/TizenRT,pillip8282/TizenRT,pillip8282/TizenRT,junmin-kim/TizenRT,junmin-kim/TizenRT,Samsung/TizenRT,pillip8282/TizenRT,Samsung/TizenRT,Samsung/TizenRT,jsdosa/TizenRT,Samsung/TizenRT,Samsung/TizenRT,junmin-kim/TizenRT,jeongarmy/TizenRT