Merge patch series "Tidy up console recording in tests"

Simon Glass <sjg@chromium.org> says:

This series started as a small fix for checking for an empty line,
but in the process several other problems were found and fixed:

- fix tests which use console recording but don't set the flag
- drop unnecessary resetting of the console in tests
- drop unnecessary blank line before MMC output
- update the docs a little
- fix buildman test failure on newer Pythons
- a few other minor things

This series also renames the confusing flag names, so that they are
easier to remember - just a UTF_ (unit-test flags) prefix.

common/console.c

@@ -846,6 +846,8 @@ int console_record_readline(char *str, int maxlen)
 {
 	if (gd->flags & GD_FLG_RECORD_OVF)
 		return -ENOSPC;
+	if (console_record_isempty())
+		return -ENOENT;
 
 	return membuff_readline((struct membuff *)&gd->console_out, str,
 				maxlen, '\0', false);