Improve s390 debug feature usage:
- log busy bit in dbf
- increase size of dbf views
- consistent logging of qdio api calls to setup view
- print subchannel number so one can associate the interface
  with the dbf data
- only log events to one view
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>