compositor: Respect WESTON_BUILD_DIR env var in weston_load_module

We were loading modules out of the system dirs unconditionally, so
tests that loaded modules would use the system ones, or fail if
they weren't installed.

Signed-off-by: Derek Foreman <derekf@osg.samsung.com>
Reviewed-By: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Jon A. Cruz <jonc@osg.samsung.com>
Reviewed-by: Bryce Harrington <bryce@osg.samsung.com>
1 file changed