compositor: refactor more into weston_surface_attach

Merge more code into a common function. No functional changes.

At every site where weston_surface_set_size_from_buffer() was called,
weston_surface_attach() was called first. Move all calls of
set_size_from_buffer into weston_surface_attach.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
1 file changed