QETH misc minor tweaks:

1. IPA_CMD_CREATEADDR tweak for IPv6 (didn't help any though).
2. process_input_queues DBGTRC tweak.
3. OSA_AQ (Activate Queues loop): drop packets if no queue.
QETH shutdown/halt tweak/fix
QETH z/VM fix: init queue vars, esp qmask (OSA working on z/VM 5.3)