audio/flite: remove flush in play_wave()

[adr <adr%sdf.org@localhost>]

Hi, this patch removes a flush call in play_wave(), which makes
parts of the text synthesized directly to the audio device be lost.

Brian if you are reading this, the old version you use doesn't have
it, don't bother. Note that the versions you use of yasr|eflite
don't work correctly with this flite, small amounts of audio are
missing at the end of the synthesis. I'll try with new versions
when I have time.

Regards,
adr

=======================
$NetBSD$

--- src/audio/audio.c.orig	2020-08-13 00:17:09.000000000 +0000
+++ src/audio/audio.c
@@ -247,7 +247,6 @@ int play_wave(cst_wave *w)
 	}
     }

-    audio_flush(ad);
     audio_close(ad);

     return CST_OK_FORMAT;

$NetBSD$

--- src/audio/audio.c.orig	2020-08-13 00:17:09.000000000 +0000
+++ src/audio/audio.c
@@ -247,7 +247,6 @@ int play_wave(cst_wave *w)
 	}
     }
 
-    audio_flush(ad);
     audio_close(ad);
 
     return CST_OK_FORMAT;