Fix stuff to make it compile (on mac)

src/examples/fluke_test.cpp

src/libDevCom/HIH6130.h

src/libGPIB/Fluke8842.cpp

src/libGPIB/Keithley24XX.cpp

src/libGPIB/Tektronix654C.cpp

src/libGPIB/include/Keithley24XX.h

src/pbv2/singleboard/longterm_noamac_test.cpp