And why would you claim MIT license on the code which you didn't write and has no license listed?
However, for a trivial piece of code as this... it could be argued it's not copyright-able and therefore you are OK... but just be careful in the future.
Unpublishing!
Many times I've emailed devs on Github regarding some code they have that I'd like to use part of but they've failed to assign a license. A few time's I've been turned away... but usually the dev just forgot or was not aware others couldn't freely use it.