glmark2: wl_surface should be destoryed after destroying wl_window

If wl_surface is destroyed while work thread is still running,
segmentation fault occurs.

Signed-off-by: Neena Busireddy <neenareddy.busireddy@nxp.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Armin Kuster <akuster808@gmail.com>