Add void in place of empty function arguments.

Since this is C89 we need to maintain this ancient practice.

Change-Id: I7223e7c38a35cf551b6e3c9159d2e21ebf7e62be
Reviewed-on: https://boringssl-review.googlesource.com/2631
Reviewed-by: David Benjamin <davidben@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>

crypto/digest/digests.c

diff --git a/crypto/digest/digests.c b/crypto/digest/digests.c
index 52d446f..ac00ed3 100644
--- a/crypto/digest/digests.c
+++ b/crypto/digest/digests.c
@@ -234,7 +234,7 @@
 
 struct nid_to_digest {
   int nid;
-  const EVP_MD *(*md_func)();
+  const EVP_MD* (*md_func)(void);
 };
 
 static const struct nid_to_digest nid_to_digest_mapping[] = {

crypto/pkcs8/pkcs8.c

diff --git a/crypto/pkcs8/pkcs8.c b/crypto/pkcs8/pkcs8.c
index 58e400d..f7fa7c1 100644
--- a/crypto/pkcs8/pkcs8.c
+++ b/crypto/pkcs8/pkcs8.c
@@ -263,8 +263,8 @@
 
 struct pbe_suite {
   int pbe_nid;
-  const EVP_CIPHER* (*cipher_func)();
-  const EVP_MD* (*md_func)();
+  const EVP_CIPHER* (*cipher_func)(void);
+  const EVP_MD* (*md_func)(void);
   keygen_func keygen;
 };
 

include/openssl/pkcs8.h

diff --git a/include/openssl/pkcs8.h b/include/openssl/pkcs8.h
index 8735387..826ac7f 100644
--- a/include/openssl/pkcs8.h
+++ b/include/openssl/pkcs8.h
@@ -135,7 +135,7 @@
 /* Deprecated functions. */
 
 /* PKCS12_PBE_add does nothing. It exists for compatibility with OpenSSL. */
-OPENSSL_EXPORT void PKCS12_PBE_add();
+OPENSSL_EXPORT void PKCS12_PBE_add(void);
 
 /* d2i_PKCS12 is a dummy function that copies |*ber_bytes| into a
  * |PKCS12| structure. The |out_p12| argument must be NULL. On exit,