Fix for BUG#8783 kill.test must always sleep 2 seconds, even if

mysql-test-run runs with --sleep=10; otherwise GET_LOCK() times out
before being killed so we get 0 instead of NULL. Verified that it
works on our powermacg5 where the test was failing.

mysql-test/t/kill.test

@@ -44,7 +44,7 @@ select get_lock("a", 10);
 connection con2;
 let $ID= `select connection_id()`;
 send select get_lock("a", 10);
--- sleep 2
+--real_sleep 2;
 connection con1;
 disable_query_log;
 eval kill query $ID;