padding area reads
returning zero, writes ignored.

Nb: original version returned -EINVAL on write attempts, which broke the
gdb test and made the test case slightly unhappy, Jan Kratochvil suggested
the change to return 0 on write attempts.

Signed-off-by: Jarod Wilson <jarod@redhat.com>
Tested-by: Jan Kratochvil <jan.kratochvil@redhat.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
M~ÎB˜