How does Mr. Antolini respond to Holden’s telephone call?

You can find the answer to this right at the beginning of
Chapter 23.  Holden has called Mr. Antolini from his parents house.  He's there visiting
Phoebe.  He doesn't say so right out, but he seems to be calling to ask if he can stay
at the Antolinis'.

The first thing Mr. Antolini asks him is
if anything is wrong. He doesn't seem too worried when Holden says he has been kicked
out of Pencey.  Then Mr. Antolini tells Holden he can come over and stay if he needs
to.

Of course, Holden will go over and stay at the
Antolinis' in Chapter 24.