Correct snafu in talk.c

When allocating the voice buffer, it's supposed to start at the beginning
of the audio buffer, not at the end of the voice buffer. ;-D

Might clear up a thing or two.

Change-Id: I94796ff21090bcc56813cdc569957a1a9178abcd

apps/talk.c

@@ -626,7 +626,7 @@ static bool restore_state(void)
     {
         size_t size;
         audio_restore_playback(AUDIO_WANT_VOICE);
-        voicebuf = audio_get_buffer(false, &size);
+        voicebuf = audio_get_buffer(true, &size);
     }
 
     return !!voicebuf;