What do you call these "rolls" on old clothes?

Those are commonly known as pills, or bobbles in the UK, though other terms may be in use depending on location. From Wikipedia:

A pill, colloquially known as a bobble, fuzzball, or lint ball is a small ball of fibers that forms on a piece of cloth. 'Pill' is also a verb for the formation of such balls.

As the Wikipedia article mentions, pill is also the verb form for this, and the form pilling is sometimes used for multiple pills together, as in:

This sweater pills like crazy! I started out picking off individual pills, but I really need a shaver thing to get rid of all the pilling.

I'm pretty sure that's lint.

Lint is the common name for visible accumulations of textile fibers and other materials, usually found on and around clothing.
Lint (Wikipedia article)

Here are the before and after photos of a carpet after a lint remover has been used:

Picture

lint
1.Clinging bits of fiber and fluff; fuzz.
American Heritage Dictionary

It's important to remember that lint can refer to this type of material found in various places, for example, pockets, carpets, clothes surfaces, even belly button (navel).
Navel lint

Wikipedia covers a lot of them.

So you may want to specify by saying clothes lint etc. Also, not all lint is created equal, if they take form of a particular shape, like balls, capsules, rolls etc, you can use different words.

In the UK I call them bobbles, "the clothes have gone bobbly."

and to double check I am not alone:

https://www.ebay.co.uk/bhp/bobble-remover

cambridge dictionary

bobble noun

​ uk (us pill) a small ball of thread that develops on clothing or furniture covered in cloth