clang-tidy: CallbackConnectionTest - errors with callable type

[billpittman]

/data/ultifi/up-cpp/test/coverage/utils/CallbackConnectionTest.cpp:589:21: error: 'callable' in capture list does not name a variable [clang-diagnostic-error]
/data/ultifi/up-cpp/test/coverage/utils/CallbackConnectionTest.cpp:593:25: error: reference to local binding 'callable' declared in enclosing function '(anonymous namespace)::CallbackTest_HandleResetBlocksWhileCallbacksRunning_Test::TestBody' [clang-diagnostic-error]

[PLeVasseur]

Closed via #316