Bud had the same thing this past summer from an IV after spending the night at the vet. He was licking it too, it was from the fur growing back.
I sprayed it (lightly) with apple bitter and he left it alone.
He didn't lick it to the point of scabs that's why I sprayed it, if there are open wounds spraying apple bitter in it would have hurt.

Since Fenway's leg is already scabby I would put antibiotic ointment on it and wrap it up. If you have apple bitter (or something like that) I'd spray the wrapping to make sure he left it alone and didn't tear it off.

You can take a sock and cut the toe out, and pulled it up over where he's licking and tape it in place.