Normal rules for Temporary Negative Levels are that if they last for 24 hours or more, you must make a save or they become permanent. The spell just says that you get a Temporary Negative Level for 1 day and doesn't mention a save or a way to calculate the DC as it isn't coming a from a monster ability like energy drain. I am assuming this means it just goes away, but wanted to be sure I wasn't missing anything.
Creatures brought back to life through breath of life gain a temporary negative level that lasts for 1 day
that lasts for 1 day
This is the important part. No matter what happens, that negative level is gone after 1 day. Even if you had to roll after 1 day to see if it becomes "permanent", it'd still disappear at the same time.