speakup: add the missing synth parameter to all io functions

So that we can avoid the spk_ttyio_synth global variable in the next
commit.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Link: https://lore.kernel.org/r/20210126222147.3848175-2-samuel.thibault@ens-lyon.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/accessibility/speakup/speakup_dectlk.c b/drivers/accessibility/speakup/speakup_dectlk.c
index ab6d61e..d75de36 100644
--- a/drivers/accessibility/speakup/speakup_dectlk.c
+++ b/drivers/accessibility/speakup/speakup_dectlk.c
@@ -289,7 +289,7 @@ static void synth_flush(struct spk_synth *synth)
 		synth->io_ops->synth_out(synth, ']');
 	in_escape = 0;
 	is_flushing = 1;
-	synth->io_ops->flush_buffer();
+	synth->io_ops->flush_buffer(synth);
 	synth->io_ops->synth_out(synth, SYNTH_CLEAR);
 }