read_from_old_location is set twice in router_reload_router_list_impl

The second mutation appears to exist so that the conditional above it can exist. Is there a reason to check the return value?

read_from_old_location = 1;
log_notice(LD_DIR, "Couldn't read %s; trying to load routers from old "
           "location %s.", fname, altname);
if ((store->mmap = tor_mmap_file(altname)))
  read_from_old_location = 1;