double fix coalescing.cu

Here:
https://github.com/parallel-forall/code-samples/blob/master/series/cuda-cpp/coalescing-global/coalescing.cu
 
lines 54 and 70 are passing a double for the second argument:
 
    checkCuda( cudaMemset(d_a, 0.0, n * sizeof(T)) );
 
 
This is not really sensible and may trigger compiler warnings like this:
 
coalescing.cu:70: warning: passing âdoubleâ for argument 2 to âcudaError_t cudaMemset(void*, int, size_t)â
 
I would recommend changing those 2 instances of 0.0 to just 0
I guess there is also a fix  for "no newline at end of file" which may have been inserted by my editor