Fix CUDA hello example and compilation with HAPI_TRACE

[minitu]

Still needs a way to pass HAPI_TRACE as defined to the header and source files in src/arch/cuda/hybridAPI.
I think this can be done by modifying the CMakeLists.txt (and maybe a couple of other places), but would need help from the Charm++ folks.

[matthiasdiener]

Something like this in the main CMakeLists.txt might work, adding after line https://github.com/UIUC-PPL/charm/blob/520585628155479ae7f50df671e21fc084274a46/CMakeLists.txt#L705:

if(TRACING)
  target_compile_definitions(cudahybridapi PRIVATE HAPI_TRACE)
endif()

[minitu]

@matthiasdiener Confirmed that does the right thing. Thanks!

[trquinn]

Tested with changa w/ projections: it runs now.