[S390] bus_id -> dev_set_name() for css and ccw busses

Convert remaining s390 users setting bus_id to dev_set_name()
or init_name.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>