Use audio_mode_t consistently

Change-Id: Icc0048b165032366a035d35e79a5887dccab8c73
diff --git a/audio/android_audio_hw.c b/audio/android_audio_hw.c
index 4a6048b..4665eab 100644
--- a/audio/android_audio_hw.c
+++ b/audio/android_audio_hw.c
@@ -836,7 +836,7 @@
     return -ENOSYS;
 }
 
-static int adev_set_mode(struct audio_hw_device *dev, int mode)
+static int adev_set_mode(struct audio_hw_device *dev, audio_mode_t mode)
 {
     /* TODO: do we care for the mode? */
     return 0;