[PATCH] hvc_console: Unregister the console in the exit routine.

Be thorough in our exit routine, since it says it is there to be so.
Unregistering without registering is safe (checked in 2.6.10).

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>