refine tok2str() buffer use

refine tok2str() buffer use

Switch RRCP and BGP functions from tok2strbuf() to tok2str() to avoid
unnecessary local buffer management. The latter function does it in a
way to allow up to 4 calls to itself from printf(). After that
tok2strbuf() remains used by tok2str() only and can be refined later.

Remove a duplicate macro and place the remaining definition into the
right file.