session.c ssh-rand-helper.c sshd.c openbsd-compat/bsd-cygwin_util.c
   openbsd-compat/setproctitle.c] Convert malloc(foo*bar) -> calloc(foo,bar)
   in Portable-only code; since calloc zeros, remove now-redundant memsets.
   Also add a couple of sanity checks.  With & ok djm@