r2039: got rid of the free() ptr in DATA_BLOB

r2039: got rid of the free() ptr in DATA_BLOB

I plan on replacing the concept by adding a generic destructor in all talloc ptrs, so you can do:

  talloc_set_destructor(ptr, my_destructor);

to setup a function that will be called on free.
(This used to be commit 957b260621c091830c01e9e8c370c199350342ec)