alsa-util: Reset hwparams_copy before the second try of buffer setup

alsa-util: Reset hwparams_copy before the second try of buffer setup

hwparams_copy needs to be reset (as it is also reset for the third and
fourth try) before the second try.

If the reset is not done and the first try fails:
D: [lt-pulseaudio] alsa-util.c: Maximum hw buffer size is 743 ms
I: [lt-pulseaudio] alsa-util.c: snd_pcm_hw_params_set_buffer_size_near() failed: Invalid argument
I: [lt-pulseaudio] alsa-util.c: snd_pcm_hw_params_set_period_size_near() failed: Invalid argument
I: [lt-pulseaudio] alsa-util.c: snd_pcm_hw_params_set_buffer_size_near() failed: Invalid argument
D: [lt-pulseaudio] alsa-util.c: Set only period size (to 1102 samples).

We have three failures and finally the fourth (only period size) succeed.

With this patch:
D: [lt-pulseaudio] alsa-util.c: Maximum hw buffer size is 743 ms
I: [lt-pulseaudio] alsa-util.c: snd_pcm_hw_params_set_buffer_size_near() failed: Invalid argument
D: [lt-pulseaudio] alsa-util.c: Set period size first (to 1102 samples), buffer size second (to 4408 samples).

We only fail with the first try, the second (period followed by buffer) is
fine.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>