[bugfix] Fix status printout in case tests are retried

[vkarak]

Fixes #1812.

[codecov-io]

Codecov Report

Merging #1814 (79e7a1e) into master (0c929f4) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #1814   +/-   ##
=======================================
  Coverage   87.60%   87.60%           
=======================================
  Files          49       49           
  Lines        7937     7937           
=======================================
  Hits         6953     6953           
  Misses        984      984           

Impacted Files	Coverage Δ
reframe/frontend/executors/__init__.py	98.19% <100.00%> (ø)

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[ekouts]

The fix looks good to me but some lines below there is another bug from my maxfail PR:

            num_completed = len(self._stats.completed())
...
            self._printer.status(
                status,
                status,
                f'Ran {num_completed}/{len(testcases)}'
                f' test case(s) from {num_checks} check(s) '
                f'({num_failures} failure(s))',
                just='center'
            )

In this line f'Ran {num_completed}/{len(testcases)}', num_completed will be only the ones that were completed in the last retry. Not sure how we to fix this simply, since completed are the ones that failed or succeeded and we cannot just sum the completed from all runs.

(edit)
Now that I think about it the number we want to print there is len(testcases) - len(self._stats.tasks()) + len(self._stats.completed()).

[vkarak]

@jenkins-cscs retry daint dom