Issue #8597: do not append 'completed'.

Because the messages are generated server side this often creates
confusing sentence construction. Remove all text from the successful
messages and rely on the server side message and the color of the
notification to communicate intent.

Signed-off-by: Yan-Fa Li <yanfali@gmail.com>
Merge pull request #36 from ceph/1-2-issue-8597

1.2 - #8597