Fix declaration without type in t_shs3.c

(cherry picked from commit 02f15f278112f7c03fb24044de169c071a786d71)

https://github.com/krb5/krb5/commit/40212c81ad305d95404f57495bbfeba9997d91e9
Author: Robbie Harwood <rharwood@redhat.com>
Committer: Tom Yu <tlyu@mit.edu>
Commit: 40212c81ad305d95404f57495bbfeba9997d91e9
Branch: krb5-1.15
 src/lib/crypto/builtin/sha1/t_shs3.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)