s390: Keep I/O interrupts enabled for all iscs.

s390: Keep I/O interrupts enabled for all iscs.

do_io_interrupt() would stop scanning further iscs if it found
an I/O interrupt it could inject. This might cause the pending
interrupt indication for I/O interrupts to be reset although there
might be queued I/O interrupts for subsequent iscs.

Fix this by reordering the logic: Inject the I/O interrupt immediately
and continue searching all iscs for queued interrupts.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>