ivi-shell: fix layout_layer.view_list is not initilized per a screen.
ivi-shell: fix layout_layer.view_list is not initilized per a screen.

This is potential bug when it supports several screens. If view_list is
initilized here, the views, which are set by the previous screen, are
cleared. So View list shall be initilized in front of wl_list_for_each
of all screens.

Signed-off-by: Nobuhiko Tanibata <92313f26b3566e64b50391ce0051fc0e1f775402@xddp.denso.co.jp>
Reviewed-by: Pekka Paalanen <0f6ae7001e34c37b02fb2c1c2573ddf8f442136a@collabora.co.uk>

kwm81/weston,krezovic/weston,Fantu/compositor-spice,Fantu/compositor-spice,giucam/weston,sir-murray/weston,kwm81/weston,Fantu/compositor-spice,Gnurou/weston,Gnurou/weston,krezovic/weston,giucam/weston,sir-murray/weston