examples/smart: fix fully removal test files in smart test
examples/smart: fix fully removal test files in smart test

Unfortunately smart test cann't clean up used files and directory during
test. This patch helps you to clean up properly.

Change-Id: Ic1eb29f4e2acf94b1fecdcdc938ffb3815eb2355
Signed-off-by: Byoungtae Cho <d399e7ab5fdc23c09a148b7028e772c5bd5c24c5@samsung.com>

JunhwanPark/TizenRT,JunhwanPark/TizenRT,JunhwanPark/TizenRT,JunhwanPark/TizenRT,JunhwanPark/TizenRT,JunhwanPark/TizenRT