cobbler: Have rc.local output go to console

cobbler: Have rc.local output go to console

Usually if something goes wrong during the rc.local run, the machine
won't be reachable to debug over the network.  Additionally, since we
reimage every machine before each job now, it's impossible to debug why
rc.local failed given a particular job.  This outputs rc.local to the
tty specified in kernel_options so we can see the output in `$hostname_reimage` run logs.

Signed-off-by: David Galloway <dgallowa@redhat.com>