test: don't require exit message to be on last line

This is useful with enabled debug output.

test/simulation/test.common

@@ -253,7 +253,7 @@ check_chronyd_exit() {
 	for i in $(seq 1 $(get_chronyd_nodes)); do
 		test_message 3 0 "node $i:"
 
-		tail -n 1 tmp/log.$i | grep -q 'chronyd exiting' && \
+		grep -q 'chronyd exiting' tmp/log.$i && \
 			! grep -q 'Adjustment.*exceeds.*exiting' tmp/log.$i && \
 			test_ok || test_bad
 		[ $? -eq 0 ] || ret=1