iotests/116: Fix reference output

iotests/116: Fix reference output

15ce94a68ca ("block/qed: bdrv_qed_do_open: deal with errp") has improved
the qed driver's error reporting, though sadly did not add a test for
it.
The good news are: There already is such a test, namely 116.
The bad news are: Its reference output was not adjusted, and so now it
fails.

Let's fix the reference output, which has the nice side effect of
demonstrating 15ce94a68ca's improvements.

Fixes: 15ce94a68ca6730466c565c3d29971aab3087bf1
       ("block/qed: bdrv_qed_do_open: deal with errp")
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210326141419.156831-1-mreitz@redhat.com>