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/crypto/x509v3/v3nametest.c b/crypto/x509v3/v3nametest.c
index d0d97ff..326b1f9 100644
--- a/crypto/x509v3/v3nametest.c
+++ b/crypto/x509v3/v3nametest.c
@@ -285,7 +285,7 @@
 	{NULL, NULL, 0}
 	};
 
-static X509 *make_cert()
+static X509 *make_cert(void)
 	{
 	X509 *ret = NULL;
 	X509 *crt = NULL;