Sound: properly round percent values

Fix #1558

Author: CarterLi

src/detection/sound/sound_linux.c

@@ -18,7 +18,7 @@ static void paSinkInfoCallback(pa_context *c, const pa_sink_info *i, int eol, vo
     ffStrbufInitS(&device->name, i->description);
     ffStrbufTrimRightSpace(&device->name);
     ffStrbufTrimLeft(&device->name, ' ');
-    device->volume = i->mute ? 0 : (uint8_t) (i->volume.values[0] * 100 / PA_VOLUME_NORM);
+    device->volume = i->mute ? 0 : (uint8_t) ((i->volume.values[0] * 100 + PA_VOLUME_NORM / 2 /*round*/) / PA_VOLUME_NORM);
     device->active = i->active_port && i->active_port->available != PA_PORT_AVAILABLE_NO;
     device->main = false;
 }

src/detection/sound/sound_nbsd.c

@@ -41,7 +41,7 @@ const char* ffDetectSound(FFlist* devices)
         ffStrbufInitS(&device->name, ad.name);
         ffStrbufTrimRightSpace(&device->name);
         ffStrbufInitF(&device->platformApi, "%s", "SunAudio");
-        device->volume = (uint8_t) (ai.play.gain * 100 / AUDIO_MAX_GAIN);
+        device->volume = (uint8_t) ((ai.play.gain * 100 + AUDIO_MAX_GAIN / 2) / AUDIO_MAX_GAIN);
         device->active = true;
         device->main = defaultDev == idev;
     }

src/detection/sound/sound_obsd.c

@@ -80,7 +80,7 @@ const char* ffDetectSound(FFlist* devices)
         if (!bundle.mute[i])
             totalLevel += bundle.level[i];
     }
-    device->volume = (uint8_t) (totalLevel * 100 / bundle.iLevel);
+    device->volume = (uint8_t) ((totalLevel * 100 + bundle.iLevel / 2) / bundle.iLevel);
 
     return NULL;
 }