I believe Huber tendered his resignation and Trump accepted. That is a normal thing to do. Sessions asked Trump for his re-appointment.
The resignation and reappointment was meant to erase the Obama stigma/stench from Huber.
“The resignation and reappointment was meant to erase the Obama stigma/stench from Huber.”
Several anons have suggested that since O was found to be ineligible, they had to re-confirm him - bwahaha!