ktest: Show name and iteration on errors

If a test has an error, display not only the what type of test failed, but
if the test was giving a name, display that too, as well as the current
iteration of the tests. Each test has an iteration number associated to it.
For error messages display that iteration number along with the test type
and test name. This includes the message that gets sent via email.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>