cdecl99: Avoid passing uninitialized value to help_print_option.

cdecl99: Avoid passing uninitialized value to help_print_option.

For options that do not take arguments, the "arg" member of the help
structure is not assigned by lopt_get_help.  Since the structure
is not otherwise initialized, it is technically undefined to even
evaluate this member in order to pass it to the help_print_option
function.

In this case, the argument is not actually used, and I'm not aware
of any actual failures as a result, but it easy enough to avoid.