[S390] cio: Correct cleanup on error.

Fix cleanup on error in chp_new() and init_channel_subsystem()
(must not call kfree() on structures that had been registered).

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>