Fact 1: Trump fires people who don’t perform well. He has no problem whatsoever saying “You’re fired!”. In fact, it’s his trademark catch phrase.
Fact 2 : Sessions is well known for his honesty and hard work. Earlier in his career when he was a prosecutor, he did not telegraph his moves.
Since Trump has not fired Sessions, it is logical to conclude that Sessions is serving some purpose for Trump. You may argue about what that purpose is, but the logical conclusion that most of us have come to is the the whole Trump/Sessions feud is kabuki theater.
I dont think that Trump would fire him now and risk the effect that it would have on the mid-terms.