PulseAudio: remove incorrect corking assertion

It can fail in rare circumstances such as context failures (in other
words, PulseAudio daemon crash or exit).
(cherry picked from commit 5a0c690f)

modules/audio_output/pulse.c

@@ -254,7 +254,6 @@ static void stream_resync(audio_output_t *aout, pa_stream *s)
     aout_sys_t *sys = aout->sys;
     mtime_t delta;
 
-    assert (pa_stream_is_corked(s) > 0);
     assert (sys->pts != VLC_TS_INVALID);
 
     delta = vlc_pa_get_latency(aout, sys->context, s);