Fix uninitialized-variable bug.

Fix uninitialized-variable bug.

For some reason, neither of the compilers I usually use noticed the
uninitialized-variable problem I introduced in commit 7e2a18a9161fee7e.
That's hardly a good enough excuse though.  Committing with brown paper bag
on head.

In addition to putting the operations in the right order, move the
declaration of "now" inside the loop; there's no need for it to be
outside, and that does wake up older gcc enough to notice any similar
future problem.

Back-patch to 9.4; earlier versions lack the time-to-SIGKILL stanza
so there's no bug.