audio: Rename HANDSET to EARPIECE to follow libsecril-client

Change-Id: I9e99e1bdf8c8c29aca4d753269190dd34c229d8a
diff --git a/audio/voice.c b/audio/voice.c
index 1965379..8d73fd1 100644
--- a/audio/voice.c
+++ b/audio/voice.c
@@ -72,7 +72,7 @@
             device_type = SOUND_AUDIO_PATH_SPEAKER;
             break;
         case AUDIO_DEVICE_OUT_EARPIECE:
-            device_type = SOUND_AUDIO_PATH_HANDSET;
+            device_type = SOUND_AUDIO_PATH_EARPIECE;
             break;
         case AUDIO_DEVICE_OUT_WIRED_HEADSET:
             device_type = SOUND_AUDIO_PATH_HEADSET;
@@ -86,8 +86,8 @@
             device_type = SOUND_AUDIO_PATH_BLUETOOTH;
             break;
         default:
-            /* if output device isn't supported, use handset by default */
-            device_type = SOUND_AUDIO_PATH_HANDSET;
+            /* if output device isn't supported, use earpiece by default */
+            device_type = SOUND_AUDIO_PATH_EARPIECE;
             break;
     }