formatters: insert missing space in unexpected pass message for report.
formatters: insert missing space in unexpected pass message for report.

* lib/specl/formatter/report.lua: Insert a missing space in the
unexpected pass message.

Signed-off-by: Gary V. Vaughan <f9023000f29773649f3850298becb9544b5fd6a9@gnu.org>

gvvaughan/specl