[PATCH] Fix new Coverity IDs

[Jeremy Allison]

On Wed, Jan 11, 2017 at 11:07:18AM -0800, Jeremy Allison wrote:
> 1501                 num_rids = talloc_array_length(rids);
> 
> so 'rids' is already initialized to NULL, but we then
> call talloc_array_length(rids) without checking if
> the return was NULL. This works (I think), but goes
> via:
> 
> #define talloc_array_length(ctx) (talloc_get_size(ctx)/sizeof(*ctx))
> 
> and talloc_get_size() is:
> 
> _PUBLIC_ size_t talloc_get_size(const void *context)
> {
>         struct talloc_chunk *tc;
> 
>         if (context == NULL) {
>                 context = null_context;
>         }
>         if (context == NULL) {
>                 return 0;
>         }
> 
>         tc = talloc_chunk_from_ptr(context);
> 
>         return tc->size;
> }
> 
> - which uses null_context - which can change what it returns
> if someone ever calls talloc_enable_null_tracking() !!!!!

Never mind. As Volker just pointed out to me on the phone,
null_context = _talloc_named_const(NULL, 0, "null_context"),
which will always return zero size anyway. Still,
that code shouldn't be in talloc_get_size().

Patch(es) to follow !