Some other places that needed buffer_ -> tagbuffer_.

("Namespaces" in C code - more fun than a barrel full of rabid monkeys on
crack.)

Change-Id: Idb0fafd9c59c55407530f8626ecdc8edef33154b
Reviewed-on: https://code.wireshark.org/review/3404
Reviewed-by: Guy Harris <guy@alum.mit.edu>