Use '__attribute__((unused))' consistently

src/entrypoints/kernel-testsuite.cpp

src/shared/diagnostic/PrintLogger.h

src/shared/events/HSM.h

src/shared/events/utils/EventCounter.h

src/shared/utils/Unused.h

src/tests/catch/xbee/test-xbee-parser.cpp

src/tests/drivers/xbee/XbeeTestData.h

src/tests/drivers/xbee/test-xbee-gui.cpp

src/tests/sensors/test-bmx160-with-correction.cpp

src/tests/sensors/test-lis3mdl.cpp

src/tests/test-hsm.cpp

src/tests/test-sensormanager.cpp