Defaulting to any file in DL_DIR as the first match for a file:// url
doesn't make much sense and can lead to unexpected results.
This patch changes the logic so this is the last fallback location
instead. Whether it should be using DL_DIR at all for this is a
good question but something for another patch.
[YOCTO #1710]
(Bitbake rev: 5597a68fac0954c682b67471722c2643e2415f99)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>