load_image: always print a message on failure if filename is not empty

It was rather inconsistent before. This may help users figure out why
backgrounds and icons don't show up. A better api where the error can
be queried might be nice, but this seems sufficient for current Weston use.

[Pekka Paalanen: removed one stray space.]

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