build: Ignore non-directories in overlay.d
So we can add a `README.md` for example to help people understand
different ones.
@@ -293,6 +293,9 @@ EOF
fi
if [ -d "${ovld}" ]; then
for n in "${ovld}"/*; do
+ if ! [ -d "${n}" ]; then
+ continue
+ fi
local bn ovlname
bn=$(basename "${n}")
ovlname="${name}-config-overlay-${bn}"
