[gtkada] Corrected patch for gdk_pixbuf_new_from_inline

[Arnaud Charlet]

> Changed to the chars_ptr_array approach. (Also changed 
> subject to correct name of routine!)

Thanks. I will most likely remove the 'Length' parameter which does not
make sense for Ada (the 'Length is already there for that purpose) and having
a default value for the first parameter does not help in general calling
this function easily.

Arno