Avoid touching the LEDs too early in the game. After the recent

Avoid touching the LEDs too early in the game.  After the recent
changes to the keyboard code in pcvt, this update_led() very often
caused pcvt to hang early at boot time.

(Eventually, a better solution should be found, but the simple
omission serves well as a workaround for something that is actually a
show-stopper class problem.)

Candidate for 2.2.