libweston: remove previous_damage from struct weston_output

The member previous_damage from struct weston_output is no longer necessary.
First, stop calling init, fini and copying output_damage to it. Then remove
it from struct weston_output.

Signed-off-by: Leandro Ribeiro <leandrohr@riseup.net>
3 jobs for cleanup_previous_damage in 1 minute and 28 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Container Prep
passed #1062220
container_prep

00:00:18

 
  Build
passed #1062221
build-native-meson-default-options

00:01:09

passed #1062222
build-native-meson-no-gl-renderer

00:00:49