Convert all zero-argument functions to '(void)'

Otherwise, in C, it becomes a K&R function declaration which doesn't actually
type-check the number of arguments.

Change-Id: I0731a9fefca46fb1c266bfb1c33d464cf451a22e
Reviewed-on: https://boringssl-review.googlesource.com/1582
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/include/openssl/evp.h b/include/openssl/evp.h
index edeb850..091912f 100644
--- a/include/openssl/evp.h
+++ b/include/openssl/evp.h
@@ -83,7 +83,7 @@
 
 /* EVP_PKEY_new creates a new, empty public-key object and returns it or NULL
  * on allocation failure. */
-OPENSSL_EXPORT EVP_PKEY *EVP_PKEY_new();
+OPENSSL_EXPORT EVP_PKEY *EVP_PKEY_new(void);
 
 /* EVP_PKEY_free frees all data referenced by |pkey| and then frees |pkey|
  * itself. */
@@ -708,10 +708,10 @@
 /* Private functions */
 
 /* OpenSSL_add_all_algorithms does nothing. */
-OPENSSL_EXPORT void OpenSSL_add_all_algorithms();
+OPENSSL_EXPORT void OpenSSL_add_all_algorithms(void);
 
 /* EVP_cleanup does nothing. */
-OPENSSL_EXPORT void EVP_cleanup();
+OPENSSL_EXPORT void EVP_cleanup(void);
 
 /* EVP_PKEY_asn1_find returns the ASN.1 method table for the given |nid|, which
  * should be one of the |EVP_PKEY_*| values. It returns NULL if |nid| is