How can I use Postgres "ROLLBACK TO SAVEPOINT" with "FOR UPDATE SKIP LOCKED"?

Postgres 10

I am trying to use "FOR UPDATE SKIP LOCKED" to make a work queue in
Postgres.

My goal is to be able to set status to 'complete' or 'failed' as the
outcome by using "ROLLBACK TO SAVEPOINT;" in the event that processing
fails.

I expected the code below to result in a final status of "failed", but it
appears the final status is "waiting".

BEGIN;
DROP TABLE IF EXISTS foo;
SELECT id
INTO foo
FROM jobs
WHERE status = 'waiting'
AND status != 'failed'
ORDER BY created ASC
FOR UPDATE SKIP LOCKED
LIMIT 1;

UPDATE jobs SET status = 'failed' WHERE id = (SELECT id from foo)
RETURNING *;
SAVEPOINT blah;
UPDATE jobs SET status = 'complete' WHERE id = (SELECT id from foo)
RETURNING *;

ROLLBACK TO SAVEPOINT blah;

Can anyone please suggest what I can do to use either COMMIT to for status
to be 'complete' or ROLLBACK TO SAVEPOINT blah for statgus to be 'failed'?

thanks!