s390/qdio: add IRQ reduction for error SBALs

SBALs in PRIMED or ERROR state represent new work on the Input Queue.
But while inbound_primed() does all sorts of ACK management for new
PRIMED work, the same handling is currently missing for ERROR work.
In particular the path for ERROR work doesn't clear up _old_ ACKs.

Treat ERROR work the same as PRIMED work, but consider that the QEBSM
auto-ACK feature doesn't apply here. So we need to set the ACK manually,
as if it was a non-QEBSM device.

Note that this doesn't aspire to actually improve performance, the main
goal is to just unify the code paths and have consistent behaviour.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>