test: fix flaky crashing.sh

Two races, both around the post:script Finit runs when it gives up on a
service.

Finit marks the service crashed before it forks post:script, so the file
the test greps for lands a moment later.  Waiting for the state is not
enough.

slay then takes the PID from initctl status, and service_post_script()
sets svc->pid to the script's PID, so once Finit has given up the PID
reported for the service is the post:script.  Killing that takes out the
script instead of the service and the file never arrives at all.  The
guard for this was already there, with a comment describing it, but
inside the loop that waits for a PID to appear, so it only covered the
case where there was none.  A PID that was already there went straight
to kill -9.  Hence the gcc leg killing once more at lap 13, after Finit
had stopped restarting, where clang stopped at 12.

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

test/skel/bin/slay

@@ -58,5 +58,15 @@ done
 
 echo "$pid" > /tmp/oldpid
 
+# The check above only runs while waiting for a PID to appear.  Finit
+# reports the post:script's PID as the service's once it has given up
+# restarting, so a PID that was already there needs the same guard:
+# killing it would take out the script instead of the service, and the
+# side effects the test is waiting for never happen.
+st=$(initctl -p status "$nm" 2>/dev/null | awk '/Status/{print $3}')
+if [ "$st" = "crashed" ]; then
+    exit 1
+fi
+
 #echo "PID $pid, kill -9 ..."
 kill -9 "$pid" 2>/dev/null || true