Attempt vsnprintf() up to BUFSIZ in kore_buf_appendv().
Attempt vsnprintf() up to BUFSIZ in kore_buf_appendv().

If the result was too large fall back to vasprintf instead.

bonifaido/kore,hhua/kore,sinemetu1/kore,bonifaido/kore,hhua/kore,jorisvink/kore,korusdipl/kore,bonifaido/kore,fourdollars/kore,hhua/kore,jorisvink/kore,zhcy/kore