Reboot from within linode
Well now you can.
Simply add the following to your .bashrc file or what ever shell rc file you use
changing cp_username for your cp username and hostxx for your host
the either logout and back in again or do a source .bashrc
You can now type reboot and you will be prompted for you password enter your CP password and your linode will the be rebooted. There may be a delay as it goes into the job queue. This is the same as doing a reboot from the CP.