cuda checkCudaErrors

#define checkCudaErrors( a ) do { \
    if (cudaSuccess != (a)) { \
    fprintf(stderr, "Cuda runtime error in line %d of file %s \
    : %s \n", __LINE__, __FILE__, cudaGetErrorString(cudaGetLastError()) ); \
    exit(EXIT_FAILURE); \
    } \
    } while(0);