libweston-desktop: Rename _destroy_view to _unlink_view

It doesn't destroy the view per se (except for internal surfaces) and
require the caller to also destroy the view itself at the appropriate
time.

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
Reviewed-by: Jonas Ã…dahl <jadahl@gmail.com>
4 files changed