VNC Acceptance test: simplify test names

The test name is composed of the class name and method name, so it
looks like there's some redundancy here that we can eliminate.

Signed-off-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190607152223.9467-7-crosa@redhat.com>
Signed-off-by: Cleber Rosa <crosa@redhat.com>