ivi-shell: ivi-shell.c, fix simple bug of assert

Signed-off-by: Nobuhiko Tanibata <NOBUHIKO_TANIBATA@xddp.denso.co.jp>
ivi-shell: ivi-shell, remove unnecessary code.

This removeing code for listener of ivi_layout_surface is already called
in ivi_layout.c. Additonally, ivisurf.ivi_layout_surface is already
cleaned up before this distroy destruction.

Signed-off-by: Nobuhiko Tanibata <NOBUHIKO_TANIBATA@xddp.denso.co.jp>
ivi-layout: remove unused function. This was called from ivi-shell.
However it is not called anymore after code clean up.

Signed-off-by: Nobuhiko Tanibata <NOBUHIKO_TANIBATA@xddp.denso.co.jp>