When rerunning an old run using kvm-again.sh, the jitter commands
will re-use the original "res" directory.  This works, but is clearly
an accident waiting to happen.  And this accident will happen with
remote runs, where the original directory lives on some other system.
This commit therefore updates the qemu-cmd commands to use the new res
directory created for this specific run.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>