Don't warn or error on variadic macros

Our portability assumptions now allow the use of variadic macros, so
don't warn or error on them.

(cherry picked from commit d211001ba17fddfb952beb00118dc5c7e598355e)

https://github.com/krb5/krb5/commit/a924075483b887ed2f386b2f16cc0091638246c6
Author: Greg Hudson <ghudson@mit.edu>
Committer: Tom Yu <tlyu@mit.edu>
Commit: a924075483b887ed2f386b2f16cc0091638246c6
Branch: krb5-1.11
 src/aclocal.m4 |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)