PulseAudio: Fix a format negotiation error.

This addresses a case when PulseAudio may negotiate S24_32 which is not
a format supported by miniaudio. This commit does two things to guard
against this:

  * The requested format is now explicitly used instead of using the
    queried format from `pa_context_get_source_info_by_name()`.

  * The `PA_STREAM_FIX_FORMAT` stream flag is no longer used as that can
    possibly negotiate something different to what we request. I.e., it
    can possibly give us S24_32 which is not usable.

miniaudio.h

@@ -31080,7 +31080,6 @@ static ma_result ma_result_from_pulse(int result)
     }
 }
 
-#if 0
 static ma_pa_sample_format_t ma_format_to_pulse(ma_format format)
 {
     if (ma_is_little_endian()) {
@@ -31107,7 +31106,6 @@ static ma_pa_sample_format_t ma_format_to_pulse(ma_format format)
         default: return MA_PA_SAMPLE_INVALID;
     }
 }
-#endif
 
 static ma_format ma_format_from_pulse(ma_pa_sample_format_t format)
 {
@@ -32140,6 +32138,9 @@ static ma_result ma_device_init__pulse(ma_device* pDevice, const ma_device_confi
         ss   = sourceInfo.sample_spec;
         cmap = sourceInfo.channel_map;
 
+        /* Use the requested format if we have one. */
+        ss.format = ma_format_to_pulse(pDescriptorCapture->format);
+
         /* Use the requested channel count if we have one. */
         if (pDescriptorCapture->channels != 0) {
             ss.channels = pDescriptorCapture->channels;
@@ -32165,7 +32166,7 @@ static ma_result ma_device_init__pulse(ma_device* pDevice, const ma_device_confi
             } else {
                 ss.format = MA_PA_SAMPLE_FLOAT32BE;
             }
-            streamFlags |= MA_PA_STREAM_FIX_FORMAT;
+            /*streamFlags |= MA_PA_STREAM_FIX_FORMAT;*/ /* Using PA_STREAM_FIX_FORMAT will make it so PulseAudio can possibly pick S24_32 which is not supported by miniaudio and will thus result in an error later on. By excluding it, PulseAudio should always pick F32. */
             ma_log_postf(ma_device_get_log(pDevice), MA_LOG_LEVEL_INFO, "[PulseAudio] sample_spec.format not supported by miniaudio. Defaulting to PA_SAMPLE_FLOAT32.\n");
         }
         if (ss.rate == 0) {
@@ -32297,6 +32298,9 @@ static ma_result ma_device_init__pulse(ma_device* pDevice, const ma_device_confi
         ss   = sinkInfo.sample_spec;
         cmap = sinkInfo.channel_map;
 
+        /* Use the requested format if we have one. */
+        ss.format = ma_format_to_pulse(pDescriptorPlayback->format);
+
         /* Use the requested channel count if we have one. */
         if (pDescriptorPlayback->channels != 0) {
             ss.channels = pDescriptorPlayback->channels;
@@ -32323,7 +32327,7 @@ static ma_result ma_device_init__pulse(ma_device* pDevice, const ma_device_confi
             } else {
                 ss.format = MA_PA_SAMPLE_FLOAT32BE;
             }
-            streamFlags |= MA_PA_STREAM_FIX_FORMAT;
+            /*streamFlags |= MA_PA_STREAM_FIX_FORMAT;*/ /* Using PA_STREAM_FIX_FORMAT will make it so PulseAudio can possibly pick S24_32 which is not supported by miniaudio and will thus result in an error later on. By excluding it, PulseAudio should always pick F32. */
             ma_log_postf(ma_device_get_log(pDevice), MA_LOG_LEVEL_INFO, "[PulseAudio] sample_spec.format not supported by miniaudio. Defaulting to PA_SAMPLE_FLOAT32.\n");
         }
         if (ss.rate == 0) {