ALSA: Don't set a start threshold when using mmap mode.

Possibly related to issue #1.

mini_al.h

@@ -5660,7 +5660,7 @@ static mal_result mal_device_init__alsa(mal_context* pContext, mal_device_type t
         return mal_post_error(pDevice, "[ALSA] snd_pcm_sw_params_set_avail_min() failed.", MAL_FORMAT_NOT_SUPPORTED);
     }
 
-    if (type == mal_device_type_playback) {
+    if (type == mal_device_type_playback && !pDevice->alsa.isUsingMMap) {   // Only playback devices in writei/readi mode need a start threshold.
         if (((mal_snd_pcm_sw_params_set_start_threshold_proc)pContext->alsa.snd_pcm_sw_params_set_start_threshold)((snd_pcm_t*)pDevice->alsa.pPCM, pSWParams, (pDevice->sampleRate/1000) * 1) != 0) { //mal_prev_power_of_2(pDevice->bufferSizeInFrames/pDevice->periods)
             mal_device_uninit__alsa(pDevice);
             return mal_post_error(pDevice, "[ALSA] Failed to set start threshold for playback device. snd_pcm_sw_params_set_start_threshold() failed.", MAL_ALSA_FAILED_TO_SET_SW_PARAMS);