test: stop.sh: Exit on first error

We want to catch regressions when syslogd dies before we can tell it to
exit.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

test/stop.sh

@@ -1,4 +1,5 @@
-#!/bin/sh
+#!/bin/sh -e
+
 if [ x"${srcdir}" = x ]; then
     srcdir=.
 fi