After some adjustments, apply the changes OpenSSL 1.0.0d on OpenVMS
submitted by Steven M. Schweda <sms@antinode.info>

apps/enc.c

diff --git a/apps/enc.c b/apps/enc.c
index c28d8b1..076225c 100644
--- a/apps/enc.c
+++ b/apps/enc.c
@@ -393,8 +393,10 @@
 
 	if (inf == NULL)
 	        {
+#ifndef OPENSSL_NO_SETVBUF_IONBF
 		if (bufsize != NULL)
 			setvbuf(stdin, (char *)NULL, _IONBF, 0);
+#endif /* ndef OPENSSL_NO_SETVBUF_IONBF */
 		BIO_set_fp(in,stdin,BIO_NOCLOSE);
 	        }
 	else
@@ -447,8 +449,10 @@
 	if (outf == NULL)
 		{
 		BIO_set_fp(out,stdout,BIO_NOCLOSE);
+#ifndef OPENSSL_NO_SETVBUF_IONBF
 		if (bufsize != NULL)
 			setvbuf(stdout, (char *)NULL, _IONBF, 0);
+#endif /* ndef OPENSSL_NO_SETVBUF_IONBF */
 #ifdef OPENSSL_SYS_VMS
 		{
 		BIO *tmpbio = BIO_new(BIO_f_linebuffer());