audio: Cleanup and fix voicecall preparation

* if (usecase == NULL) should actually be if (vc_usecase == NULL)
 * Avoid unnecessary if-block indentation by updating the control
   flow

Change-Id: If00ac405a1eac429862b953580e8614227015134

audio/audio_hw.c

@@ -905,28 +905,29 @@ static int select_devices(struct audio_device *adev,
     }
     active_out = (struct stream_out *)usecase->stream;
 
-    if (usecase->type == VOICE_CALL) {
-        out_snd_device = get_output_snd_device(adev, active_out->devices);
-        prepare_voice_session(adev->voice.session, active_out->devices);
-        in_snd_device = get_input_snd_device(adev, active_out->devices);
-        usecase->devices = active_out->devices;
-    } else {
+
     /*
      * If the voice call is active, use the sound devices of voice call usecase
      * so that it would not result any device switch. All the usecases will
      * be switched to new device when select_devices() is called for voice call
      * usecase.
      */
-        if (adev->voice.in_call) {
+    if (usecase->type != VOICE_CALL && adev->voice.in_call) {
         vc_usecase = get_usecase_from_id(adev, USECASE_VOICE_CALL);
-            if (usecase == NULL) {
+        if (vc_usecase == NULL) {
             ALOGE("%s: Could not find the voice call usecase", __func__);
         } else {
             in_snd_device = vc_usecase->in_snd_device;
             out_snd_device = vc_usecase->out_snd_device;
         }
     }
-        if (usecase->type == PCM_PLAYBACK) {
+
+    if (usecase->type == VOICE_CALL) {
+        usecase->devices = active_out->devices;
+        prepare_voice_session(adev->voice.session, active_out->devices);
+        out_snd_device = get_output_snd_device(adev, active_out->devices);
+        in_snd_device = get_input_snd_device(adev, active_out->devices);
+    } else if (usecase->type == PCM_PLAYBACK) {
         usecase->devices = active_out->devices;
         in_snd_device = SND_DEVICE_NONE;
         if (out_snd_device == SND_DEVICE_NONE) {
@@ -949,7 +950,6 @@ static int select_devices(struct audio_device *adev,
             }
         }
     }
-    }
 
     if (out_snd_device == usecase->out_snd_device &&
         in_snd_device == usecase->in_snd_device) {