Commit d7a68be4,
'tty: Only perform flip buffer flush from tty_buffer_flush()',
removed buffer flushing from flush_to_ldisc().

Fix function header comment which describes the former behavior.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>