ALSA: pcm: fix playback silence - use the actual new_hw_ptr for the threshold mode

The snd_pcm_playback_hw_avail() function uses runtime->status->hw_ptr.
Unfortunately, in case when we call this function from snd_pcm_update_hw_ptr0(),
this variable contains the previous hardware pointer. Use the new_hw_ptr
argument to calculate hw_avail (filled samples by the user space) to
correct the threshold comparison.

The new_hw_ptr argument may also be set to ULONG_MAX which means the
initialization phase. In this case, use runtime->status->hw_ptr.

Suggested-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Link: https://lore.kernel.org/r/20230505155244.2312199-2-oswald.buddenhagen@gmx.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>