[Fix #2105] Fix no comment syntax defined message when loading buffer after running failing test

[mallt]

This PR fixes the no comment syntax defined message when loading a buffer after running a failing test, by adding a save-excursion to make sure the loaded buffer does not lose focus.

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[bbatsov]

Isn't it enough to wrap this just cider--quit-error-window for this? I also wonder if we shouldn't have the save-excursion in it instead.

[mallt]

I think you're right, thanks! During testing it seemed the removal of the overlays also caused switching of the focus but I can't seem to reproduce that now... I will give it some further testing and update the PR.

[bbatsov]

Thanks!