In 913d7c15f7 stricter error checking was
introduced to the strtol call, which broke reading backlight values.
Since every sysfs backlight file ends with a newline.
As noted in a comment in the previous MR to prevent damaged pointers
after calling asprintf, replace every asprintf call with str_printf.
Previous-MR: https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/543
Signed-off-by: Sören Meier <soerenmeier@livgood.ch>
Move the DRM-backend into a new sub-directory to make it stand out from
libweston core. This facilitates splitting drm.c into more files later.
vaapi-recorder is used only by DRM-backend, move that too.
libbacklight is used only by DRM-backend and a manual test program, and is
moved as well.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>