Address Robert's feedback

*** 54,64 ****
  xrealloc(sysdem_ops_t *ops, void *p, size_t oldsz, size_t newsz)
  {
          if (newsz == oldsz)
                  return (p);
  
!         ASSERT3U(newsz, >, oldsz);
  
          void *temp = zalloc(ops, newsz);
  
          if (temp == NULL)
                  return (NULL);
--- 54,64 ----
  xrealloc(sysdem_ops_t *ops, void *p, size_t oldsz, size_t newsz)
  {
          if (newsz == oldsz)
                  return (p);
  
!         VERIFY3U(newsz, >, oldsz);
  
          void *temp = zalloc(ops, newsz);
  
          if (temp == NULL)
                  return (NULL);
*** 76,86 ****
  def_free(void *p, size_t len)
  {
          free(p);
  }
  
! /* BEGIN CSTYLED */
! sysdem_ops_t *sysdem_ops_default = &(sysdem_ops_t){
          .alloc = malloc,
          .free = def_free
  };
! /* END CSTYLED */
--- 76,85 ----
  def_free(void *p, size_t len)
  {
          free(p);
  }
  
! static sysdem_ops_t i_sysdem_ops_default = {
          .alloc = malloc,
          .free = def_free
  };
! sysdem_ops_t *sysdem_ops_default = &i_sysdem_ops_default;