Check i before r[i].

PR#3244
(cherry picked from commit 9614d2c676ffe74ce0c919d9e5c0d622a011cbed)

ssl/s3_srvr.c

@@ -1896,7 +1896,7 @@ int ssl3_send_server_key_exchange(SSL *s)
 			SSLerr(SSL_F_SSL3_SEND_SERVER_KEY_EXCHANGE,SSL_R_UNKNOWN_KEY_EXCHANGE_TYPE);
 			goto f_err;
 			}
-		for (i=0; r[i] != NULL && i<4; i++)
+		for (i=0; i < 4 && r[i] != NULL; i++)
 			{
 			nr[i]=BN_num_bytes(r[i]);
 #ifndef OPENSSL_NO_SRP
@@ -1931,7 +1931,7 @@ int ssl3_send_server_key_exchange(SSL *s)
 			}
 		d = p = ssl_handshake_start(s);
 
-		for (i=0; r[i] != NULL && i<4; i++)
+		for (i=0; i < 4 && r[i] != NULL; i++)
 			{
 #ifndef OPENSSL_NO_SRP
 			if ((i == 2) && (type & SSL_kSRP))