samples/admin/secdom/secdom.c contains implicit type casts

[Leyrer-PNP]

secdom.c:455:17: warning: conversion from 'long unsigned int' to 'WORD' {aka 'short unsigned int'} may change value [-Wconversion]
  455 |     ValueLength -= sizeof(WORD);
      |     ~~~~~~~~~~~~^~~~~~~~~~~~~~~
secdom.c:491:35: warning: conversion from 'size_t' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
  491 |         *pInfoLen = strlen(*pInfo)+1;
      |                     ~~~~~~~~~~~~~~^~

Casts should be made explicit to get rid of compiler warnings.