utils/ping: static analysis - fix memory leckage
utils/ping: static analysis - fix memory leckage

This patch fix memory leckage.

Change-Id: Ie4020378076a7ff5adf6614cc0d977f3c8ff8740
Signed-off-by: Byoungtae Cho <d399e7ab5fdc23c09a148b7028e772c5bd5c24c5@samsung.com>

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