Simplify error handling during css initialization by moving the error
handling code to setup_css (which now cleans up after itself).

Also remove the odd special cleanup handling of the pseudo_subchannel.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: NPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>