Fixing infot.mod for NEURON 9.0.0

[iomaganaris]

With the current version of infot.mod I get the following warning when compiling with NEURON 9.0.0:

 -> Compiling infot.cpp
infot.cpp: In function ‘double entropxfgxp(void*)’:
infot.cpp:1103:25: warning: argument 1 value ‘18446744072709551617’ exceeds maximum object size 9223372036854775807 [-Walloc-size-larger-than=]
 1103 |   pXP = (double*) calloc(szp,sizeof(double));
      |                   ~~~~~~^~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/9/cstdlib:75,
                 from /usr/include/c++/9/stdlib.h:36,
                 from infot.cpp:5:
/usr/include/stdlib.h:542:14: note: in a call to allocation function ‘void* calloc(size_t, size_t)’ declared here
  542 | extern void *calloc (size_t __nmemb, size_t __size)
      |              ^~~~~~