os/tools/mkconfigvars: remove an execution file, kconfig2html at end of script
os/tools/mkconfigvars: remove an execution file, kconfig2html at end of script

The kconfig2html is an artifact of mkconfigvars.sh script and it is used
only in this script and we don't support removing it.
After running this script, it is not neceessary anymore.
Let's remove it at end of script execution.

Signed-off-by: sunghan-chang <c954e25285721d8faa8b1a5c1ae2ef5a35338d32@samsung.com>

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