revlog: fix index computation during inline->non-inline transition
The computation in 63edc384d3b7 failed to factor in the index entries
themselve as revlog.start() doesn't count them. Found by Valtenin
Gatienbaron with a more precise test case from me.
Differential Revision: https://phab.mercurial-scm.org/D10724
import os
def killme(ui, repo, hooktype, **wkargs):
os._exit(80)