Commit d506a51a meant to check for
QEMU_CAPS_DRIVE_IOTUNE_MAX, but checked for QEMU_CAPS_DRIVE_IOTUNE
instead.  That's clearly visible from the diff, but it got in.  Because
of that, we were supplying information unknown for QEMU if it wasn't new
enough and we couldn't even properly handle the error, leading to
"Unexpected error".  Also iops_size came at the same time with all the
other "_max" options, so check whether we're not setting that either if
QEMU_CAPS_DRIVE_IOTUNE_MAX is not supported.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1224053Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>