hdf5_ep

[svn-r21258] Issue 7674 - clang compiler reported an error with line 334:
   temp_point->l = (unsigned long long)((i * 100 + j * 1000) * n);
The value can overflow the signed int before being converted to unsigned long long.  So I changed it to 
   temp_point->l = (unsigned long long)((i * 40 + j * 400) * n);
to keep it under the maximal value.

Tested on jam.  Simple change.