CopyBuffer benchmark calls clEnqueueFillBuffer with pattern_size > size which the CL spec requires to fail

[karolherbst]

The OpenCL spec states for clEnqueueFillBuffer:

clEnqueueFillBuffer returns CL_SUCCESS if the function is executed successfully. Otherwise, it returns one of the following errors:
CL_INVALID_VALUE
if size is not a multiple of pattern_size

This behavior can be seen with ./memory_benchmark_ocl --test=CopyBuffer --size=1 --contents=Zeros --compressedSource=0 --compressedDestination=0 --useEvents=1