emit "ECDHE" instead of "EECDH" for kX packet trace output

other parts of packet tracing emit the standard "ECDHE" label instead
of "EECDH".  This change brings the output of ssl_print_client_keyex()
and ssl_print_server_keyex() into accordance with the standard term.

ssl/t1_trce.c

@@ -817,7 +817,7 @@ static int ssl_get_keyex(const char **pname, SSL *ssl)
 		}
 	if (alg_k & SSL_kEECDH)
 		{
-		*pname = "EECDH";
+		*pname = "ECDHE";
 		return SSL_kEECDH;
 		}
 	if (alg_k & SSL_kECDHr)