preproc: reserve space for terminal NUL in %strcat
preproc: reserve space for terminal NUL in %strcat

Technically, this is not necessary, because make_tok_qstr_len()
doesn't rely on NUL termination, and in fact it *can't*, since the
string might contain embedded NULs, but tacking on a NUL is good for
debugging if nothing else. That means reserving space for it!

Reported-by: C. Masloch <33adfa7aa2bbcf32c58163f4aa6af99d90610803@ulukai.org>
Signed-off-by: H. Peter Anvin (Intel) <8a453bad9912ffe59bc0f0b8abe03df9be19379e@zytor.com>

techkey/nasm,techkey/nasm,techkey/nasm,techkey/nasm,techkey/nasm