Code cleanup for compiler warnings and volatile declarations.

src/fe/commData3.c

src/fe/controllerIop.c

src/fe/timing.c

src/include/drv/daqLib.c

src/include/drv/gsc16ai64.c

src/include/drv/gsc16ai64.h

src/include/drv/iop_adc_functions.c

src/include/drv/time_slave_io.c