Change int values to macro defined int values

[andrewkallai]

https://github.com/SOLLVE/sollve_vv/blob/b628bffba66d6b5dc19f83d12dd083a6c0070f6f/tests/5.1/target/test_target_memcpy_rect_async_no_obj.c#L26
https://github.com/SOLLVE/sollve_vv/blob/4a432b4859c5e149b7f3296b830b926b8bbf6753/tests/5.1/target/test_target_memcpy_rect_async_depobj.c#L26
Change to:
const size_t volume[2] = {N, M};
A similar suggestion was made for the Fortran tests in PR725, 726